Does AS SSD Benchmark Work on Windows 11? What to Expect from the 2020 Final Version

Short answer: yes, in practice — with an honest caveat. AS SSD Benchmark’s final version, 2.0.7316.34247, was built in January 2020, well before Windows 11 existed, and Windows 11 has never appeared in its official system listings. What we can say, and all we claim, is that community experience shows the program running on Windows 11 and producing normal results. This guide sets out exactly what is documented, what is community-tested, and where the untested edges are.

Before you start: back up important files on the drive you are troubleshooting. Most checks below are read-only, but the fixes that touch BIOS settings, partitions or drivers should never be attempted without a current backup.

What is actually documented

Keep the three layers separate, because Windows 11 pages on the internet routinely blur them. Documented: the final version is 2.0.7316.34247 from January 2020, it is freeware by Alexej Schepeljanski, and the system list recorded by Softpedia for this version covers Windows XP through Windows 10. Also documented: the program requires .NET Framework (no specific version is stated) and is portable, needing no installation. Not documented: any statement by the developer about Windows 11 support, optimisation or testing. The program has had no new version since 2020, so no later “Windows 11 update” exists — be wary of any download claiming to be one.

Community-tested: users have run this exact build on Windows 11 and benchmarked SATA and NVMe drives with it, and that hands-on experience — not a vendor promise — is the basis for saying it works. That is normally enough for a small portable benchmark, but it is a different kind of assurance from official support, and this page will not dress it up as more than it is. If your standard is “only runs software its maker certifies for this OS,” a 2020 tool will not meet it on Windows 11; if your standard is “runs correctly in real use,” community experience says it does.

How to run it cleanly on Windows 11

Use a fresh, verified copy and treat Windows 11 like any other install. Download via our download page, which links to the official alex-is.de file and publishes the SHA-256 hash verified by direct download, then extract the whole ZIP to an ordinary folder and keep the exe together with its en-US folder — otherwise the interface may open in German, the program’s default when the language files are missing. Launch it, select the drive, and run the default 1 GB test first. On a typical Windows 11 machine that is the entire procedure: no compatibility mode, no special settings.

Two ordinary Windows behaviours can interrupt a first run. SmartScreen or your security software may prompt on an unfamiliar portable exe — the correct response is to run only a copy whose hash you have verified, not to disable protection. And if the program needs direct device access for a test, an administrator launch is the standard remedy, exactly as on Windows 10; the related “Could not open physical device” case is covered in its own guide. Our startup guide covers the remaining launch failures at AS SSD Benchmark won’t start.

Compatibility settings: what helps and what is theatre

Windows’ compatibility modes are the most over-prescribed fix for this program. Because the build already runs natively on the Windows generations either side of it, forcing a Windows 7 or Windows 8 compatibility shim usually changes nothing except adding a variable. Try a plain launch, then an administrator launch; reach for compatibility settings only if both genuinely fail, and remove them again if they make no difference so the next person (probably you, in six months) is not debugging a shim nobody remembers adding.

Scaling and display settings are the other harmless oddity: on high-DPI Windows 11 displays, a 2020-era window may render small or slightly soft. That is cosmetic. It does not affect the measurements, and Windows’ display-scaling override in the exe’s properties is a safe, reversible way to make the window comfortable if it bothers you. Resist registry-based “compatibility fixes” found in old threads — for a portable benchmark they are risk without reward, and nothing in this guide requires one.

Reading Windows 11 scores honestly

A score earned on Windows 11 is read exactly like a score earned anywhere else: check the header (AHCI driver such as storahci, alignment OK), compare like-for-like test sizes, and remember the simplified scoring shape — Read = Seq × 0.1 + 4K + 4K-64Thrd, with the 4K rows doing the heavy lifting. Windows 11 itself is neither a bonus nor a penalty in the formula. If a result disappoints, the cause will be the usual suspects — controller mode, alignment, a nearly full drive, background Windows Update or sync activity in a young install — all worked through in the low-score checklist.

One Windows 11 habit deserves a specific mention: a new or newly upgraded system is rarely idle. Indexing, updates, cloud restore and app installs can run for hours after setup, and a benchmark taken in that window measures the storm, not the machine. Let a fresh Windows 11 install settle, reboot once, pause the obvious background work, and then benchmark. Reviewers’ numbers, whatever OS they used, came from settled systems.

The untested edges: ARM, virtual machines and unusual storage

Honesty requires a separate box for the configurations community experience does not cleanly cover. Windows 11 on ARM runs x86 programs through emulation, and whether this 2020 benchmark installs its device access correctly, reports the storage path faithfully and produces meaningful numbers under that emulation has not been verified here — treat ARM as “try it and judge carefully,” and do not compare emulated results against native ones. The same caution applies inside virtual machines generally, where the “physical device” is virtualised and both access errors and flattering or misleading scores are possible depending on how the host presents storage.

Unusual storage paths — drives behind certain USB enclosures, RAID volumes and storage-pool arrangements — sit in the same category on any Windows version: the program may work, may refuse the device, or may measure the bridge/pool layer more than the drive. None of that is a Windows 11 defect. Test on a direct internal connection when the number actually matters, and keep the method notes with the result so future comparisons stay honest. For the standard method itself, see how to use AS SSD Benchmark.

Verdict for Windows 11 users

Download the final 2020 build from a verified source, extract it completely, run it plainly, and expect it to work — that is the community-tested reality, stated without inventing an official Windows 11 certification the developer never issued. If it misbehaves, you are almost certainly looking at an extraction, permission or background-load problem covered in this cluster, not an OS incompatibility. And when it works — as it does on the Windows 11 machines it is run on every day — you get the same header warnings, the same Seq/4K/4K-64Thrd/Acc.time rows and the same honest scores the tool has produced since 2020. Old, finished and still useful is a fair description of both the program and, increasingly, the benchmark results it gives you on a modern system.

Why AS SSD Benchmark Is So Slow on a Hard Drive — and What to Do Instead

AS SSD Benchmark was designed for SSDs, but it will run on a mechanical hard drive — if you have the patience. On an HDD the full suite can take the better part of an hour, and first-time users routinely assume the program has frozen. It usually has not. This guide explains why hard drives crawl through these particular tests, which parts you can safely skip, and the few HDD numbers that are still worth reading when the run finally finishes.

Before you start: back up important files on the drive you are troubleshooting. Most checks below are read-only, but the fixes that touch BIOS settings, partitions or drivers should never be attempted without a current backup.

Why it is slow: physics, not a fault

An SSD answers a request electronically, in fractions of a millisecond. A hard drive answers by physically moving heads to a spinning platter — fast in human terms, glacial in benchmark terms. AS SSD Benchmark’s hardest tests for an HDD are exactly the ones that multiply those physical trips: the random 4K tests scatter thousands of tiny requests across the drive, and the access-time test measures response across the full stroke of the drive. Sequential tests, which read or write one continuous stream, are far kinder and finish comparatively quickly because the heads can settle into a single sweeping motion.

The program runs six synthetic tests and three copy tests, with the synthetic tests bypassing the operating system cache, so there is no cache to rescue the hard drive from its own mechanics. Multiply small random operations by mechanical seek time and the arithmetic is unavoidable: tens of minutes is a normal order of magnitude for a full run on an HDD, and a slow, nearly full or heavily fragmented-era drive can take longer. A progress display that creeps is a working test. A test you should worry about is one where the drive itself is clicking, disappearing from Windows or producing read errors — that is a hardware emergency, not a benchmark (see the last section).

Before you start an HDD run: protect the data first

If this hard drive holds anything you care about, back it up before benchmarking it — not after. A full benchmark is sustained, heavy work, and a drive that is already marginal can fail under load. That is true for SSDs too, but it matters most for old mechanical drives whose remaining life is unknown. AS SSD Benchmark provides no SMART, health or temperature information — it cannot tell you the drive is dying — so do not treat “the benchmark completed” as a clean bill of health, either.

Then set the test up to waste as little time as possible: close other programs so nothing else is competing for the heads, use the default 1 GB test size (the larger 3, 5 and 10 GB options multiply the work for no extra insight on an HDD), and make sure the machine will not sleep mid-run. A laptop on battery that suspends at 40% through a benchmark helps nobody.

What you can skip, stop or ignore

You do not owe the program a complete run. If your question is simply “is this old drive still behaving like a normal hard drive?”, the sequential row plus a completed access-time reading already answer most of it, and you can stop the run once you have the rows you came for rather than waiting out every copy scenario. The Copy-Benchmark’s three scenarios — ISO (large files), Program (many small files) and Game (a mix) — are interesting for comparing file-copy behaviour, but Program in particular is another small-file marathon on an HDD; skip the full copy suite unless copying program folders is literally the workload you are evaluating.

Ignore the total score as a judgement of the HDD. The score formula weights the 4K tests that mechanical drives are worst at, so any HDD total will look catastrophic next to any SSD total. That gap is the technology gap, not your drive underperforming its peers. Comparing your HDD’s total to an SSD’s total tells you what you already knew: you are benchmarking a spinning disk with an SSD ruler. Judge the drive against hard-drive expectations instead — the next section shows how.

The HDD numbers that are still useful

Sequential read and write remain meaningful: a healthy desktop HDD should deliver a smooth, sustained sequential result in the range its generation is known for, and a sequential result that collapses or swings wildly suggests fragmentation-era clutter, a failing area of the platter or a connection problem worth investigating. Access time is the second useful figure: it exposes how hard the mechanics are working, and a drive whose access times have grown dramatically versus its own past results is a drive to watch — ideally with a real health tool, since AS SSD Benchmark cannot show SMART data.

The 4K rows are still useful as a baseline for one specific decision: demonstrating, in your own numbers, why an SSD upgrade transforms everyday responsiveness. Operating systems live on small random reads and writes. Saving your HDD run (the program can export results and screenshots from its File menu) and later placing it beside the same test on an SSD is the most persuasive upgrade justification there is — far better than quoting a stranger’s screenshot. Our general low-score checklist and 4K guide apply to that SSD run when you make it.

When slowness means stop, not wait

Stop the test and back up immediately if the drive makes new repetitive clicking or grinding noises, if Windows reports read/write errors during the run, if the drive vanishes from Explorer or Disk Management, or if a test row truly never advances while the drive light stays solid and the system stutters. Those are failure behaviours, and every extra minute of benchmarking is a minute not spent copying the data off. In that situation the benchmark has already given you its most important result: the drive cannot be trusted.

If the drive is merely slow-but-healthy, the decision is economic. An old HDD that still completes its work is a fine bulk-storage or backup-target drive. As a Windows system drive in a machine you use daily, though, its 4K and access-time numbers explain every laggy boot and stuttering program launch you have been tolerating — and no setting in AS SSD Benchmark, Windows or BIOS will change mechanical physics.

The sensible upgrade path

When you are ready, the workflow is simple: install or clone to an SSD, keep the HDD as secondary storage, and re-run AS SSD Benchmark on the SSD to establish its clean baseline. Choosing the SSD on interface and capacity for your machine — rather than on a headline score — is covered in our NVMe buying guide, and the program itself is a two-minute download from our download page when you need a fresh copy. Keep the old HDD result file. Months later, when the upgrade’s novelty has faded, that slow, patient, nearly hour-long run is the receipt that proves how far the machine came — and a reminder of why nobody benchmarks a hard drive twice for fun. For the SSD-side method, start with how to use AS SSD Benchmark.

AS SSD Benchmark Won’t Start or Closes Immediately — Startup Troubleshooting

You double-click AS SSD Benchmark and nothing useful happens: no window, a window that flashes and vanishes, or a German interface you never asked for. Because the program is a small, portable tool from 2020, startup failures almost always trace back to how the files were extracted, what Windows is missing, or what is blocking it. Work through this guide in order — and note that this site makes no claim that any file has passed a particular scan; instead, you will verify your copy yourself against the published hash.

Before you start: back up important files on the drive you are troubleshooting. Most checks below are read-only, but the fixes that touch BIOS settings, partitions or drivers should never be attempted without a current backup.

Symptom map: match your case first

A brief flash and then nothing usually means the program started and exited immediately — a missing runtime component, a blocked launch or an incomplete extraction. No reaction at all can mean the launch is being silently blocked or the file association/extraction is broken. A window that opens in German is a different, simpler case: the program ran, but it could not find its English language files, so it fell back to its default German interface — the developer’s own language. Each case has a different first fix, so identify yours before changing settings at random.

Whatever the symptom, start from a known-good position: an intact copy of the final version, 2.0.7316.34247, fully extracted to an ordinary folder such as a Benchmark folder inside your Documents or on the desktop. Troubleshooting a copy that lives inside a ZIP preview, a cloud-synced folder or a read-only location adds variables you do not need.

Check 1: the files must stay together

AS SSD Benchmark is portable and needs no installation, but portable does not mean a single loose file. The download is a ZIP containing the executable plus a language folder (en-US). The exe expects that folder beside it. If you copied only the exe to your desktop, or your unzip tool dropped the folder, the program can misbehave or default to German. Fix: extract the entire ZIP again to a fresh folder, keep the exe and the en-US folder together in it, and launch from there. If the interface is German but the folder is present, use the program’s Language menu to select English once it is running.

Also confirm you are launching the real exe, not a shortcut left over from an older copy or a similarly named file from an unrelated bundle. Old download folders accumulate versions; a 1.x-era copy carries old bugs — including the physical-device bug fixed in the final build, detailed in our physical-device guide — and is not worth debugging. Replace, do not repair.

Check 2: .NET Framework must be present and enabled

AS SSD Benchmark requires .NET Framework — that requirement is documented, but no specific version number is officially stated for this program, so be suspicious of any page that insists on a precise version as gospel. On a current Windows install the framework is normally present; on stripped-down, very old or modified installs it may be disabled or damaged. The generic, safe checks are: open Windows’ “Turn Windows features on or off” panel and confirm the .NET Framework entries are enabled; run Windows Update to completion, since framework servicing arrives through it; and, if the framework itself appears damaged, use Microsoft’s own repair options for your Windows version. Restart after any framework change before testing the program again.

Caution: download framework installers and repair tools only from Microsoft. Third-party “DLL fixer” and driver-updater bundles are a classic malware vector and will never be the right answer to a benchmark that will not start. If a site bundles AS SSD Benchmark with extra installers or demands you disable security software to run it, walk away from that copy entirely.

Check 3: permissions and security-software blocks

Try launching once with Run as administrator. Some operations the program performs at startup and during testing — above all, opening the physical device — can be denied in a standard session, and a program that is denied early may simply close. If it starts as administrator, you have learned the block is permission-related; you can keep using that launch method for benchmarking rather than weakening system-wide settings.

Security software is the other common silent blocker for small portable utilities. Check your antivirus history or quarantine log for the exe before assuming anything, and restore/allow only a copy you have verified against the official hash (next check). Do not disable your antivirus wholesale to “see if it helps,” and do not add broad folder exclusions for a download directory. The precise, reversible allow for one verified file is the professional move; anything broader trades a benchmark for a real risk.

Check 4: re-download from the official file and verify the hash

If the copy’s history is uncertain, stop patching it and replace it. Our download page links to the official file served by alex-is.de and publishes the verification data: the ZIP is 266,905 bytes, with SHA-256 56b80a3dde4537a77f9f7fb6bf45372b9b3d0a75e030d5373e5661913d7ef057 and MD5 6ce42c4feddac8262ad67f37bd0c0dd1 — values obtained by downloading the official file directly and hashing it on 2026-10-22. Compare your download’s hash with a built-in tool (for example, the Get-FileHash command in PowerShell) before you run anything. A mismatch means the file is incomplete or not the official package: delete it and download again rather than troubleshooting a suspect binary.

Once a verified, fully extracted copy is in place, most startup failures are already gone, because most were never the program’s fault. If a verified copy still will not start on this PC, try it on another Windows PC if one is available: a copy that runs elsewhere proves the program is fine and focuses attention on this system’s framework, permissions or security stack. For Windows 11 machines specifically, see also our Windows 11 guide and the first-run walkthrough in how to use AS SSD Benchmark.

What not to do, and when to stop

Do not install “compatibility packs,” random runtime bundles or patched executables offered in forum replies; do not run the program permanently with security software disabled; and do not edit the registry to chase a launch failure unless a documented, reversible step for your exact Windows version calls for it — registry edits made on a guess have a way of outliving the problem they were meant to solve. Every check in this guide is reversible, and that is deliberate.

If you reach the end with a verified final-version copy, framework enabled, administrator launch tried, no security block logged and a second PC running the same files happily, the remaining variable is this Windows installation itself. At that point, system-level repair is a bigger job than a benchmark justifies on its own — note the findings, keep the verified copy for the next machine or the next clean install, and benchmark there. A tool that takes two minutes to run should never cost you an afternoon of system surgery.

Low 4K and 4K-64Thrd Scores in AS SSD Benchmark — Causes and Step-by-Step Checks

Sequential numbers look fine, but the 4K rows are in single figures and 4K-64Thrd barely improves on them — so the total score, which weights those rows heavily, collapses. This pattern has a short list of usual causes, and most of them are settings rather than the SSD. This guide explains what the two 4K tests measure, why IDE mode and misalignment hit them first, and the order in which to check everything else.

Before you start: back up important files on the drive you are troubleshooting. Most checks below are read-only, but the fixes that touch BIOS settings, partitions or drivers should never be attempted without a current backup.

What the 4K rows actually measure

The 4K test measures random reads and writes of tiny 4 KB blocks, one operation at a time. The 4K-64Thrd test measures the same small-block pattern spread across 64 threads, queuing many operations at once — the workload where a drive’s controller, its command queuing and the host interface all have to work together. AS SSD Benchmark runs six synthetic tests plus three copy tests without using the operating system cache for the synthetic set, so these rows reflect the drive path, not memory speed.

Two expectations to set before troubleshooting. First, single-thread 4K numbers are always dramatically smaller than sequential numbers, on every drive ever made — small random operations simply cannot stream. A “low-looking” 4K read next to a huge sequential read is physics, not a fault. Second, the gap between 4K and 4K-64Thrd is itself diagnostic: on a healthy AHCI setup the threaded test should pull well ahead on reads because queued operations can be served efficiently. When 4K-64Thrd refuses to rise above plain 4K, something is preventing effective queuing — and that something is the target of this guide.

Cause 1: IDE mode (pciide) — the queue killer

Native Command Queuing is an AHCI feature. In IDE mode there is no NCQ for the drive to exploit, so the 64-thread test loses its main advantage and 4K-64Thrd scores sag exactly as described above. Check the header of the AS SSD window first: pciide – BAD confirms this cause in one glance. The fix is a controller-mode change in BIOS/UEFI with Windows prepared beforehand — a job with a genuine boot-failure risk if rushed. Follow the pciide – BAD guide in full, backup included, and use the mode check to see every drive’s state before you start.

If the header already shows storahci or msahci, queuing is available and the cause lies elsewhere — do not change BIOS settings that are already correct. Note the driver word down and move on; our storahci explainer covers why either Microsoft driver name is fine.

Cause 2: misalignment and write-side pain

A misaligned partition forces extra work on small writes in particular, so suspect alignment when 4K writes and 4K-64Thrd writes disappoint while reads look healthier. The header reports alignment next to the driver: BAD there is your confirmation. The remedies — leave it, realign with a partition tool at your own risk, or reinstall/re-clone cleanly — are compared honestly in the alignment BAD guide, and the alignment check shows how to record the offset before deciding. As with every partition job: back up first, and never promise yourself a lossless outcome from an in-place tool.

While you are looking at writes, check free space. A nearly full SSD has little room for its internal housekeeping, and small random writes are the first casualty. Freeing real space and letting the drive idle before a retest is a boring fix that regularly works.

Cause 3: CPU, power and background competition

Sixty-four threads of small operations need the host awake and responsive. A laptop on battery with an aggressive power plan, a CPU being held back by power limits, or a system quietly running updates, sync and antivirus scans will post 4K numbers that say more about the moment than the drive. For a diagnostic run: mains power connected, a performance-oriented power plan, a fresh reboot, background disk work paused, and no other drive utilities open. Then run the test twice and compare — consistency between runs is itself a health sign.

Thermal behaviour belongs here too. Sustained testing warms an NVMe drive, and a throttling drive fades as the run progresses. AS SSD Benchmark reports no temperatures, so if you suspect heat, watch it with the drive maker’s tool or a hardware monitor during a run, and think about airflow and heatsinking only once you have seen the temperature actually climb. Guessing at heat without a reading wastes money.

A clean retest protocol

• Reboot, connect mains power, and pause updates, sync and scans.
• Confirm the header: AHCI driver shown, alignment OK — or note which one is not.
• Leave the system idle for a few minutes so internal drive housekeeping can settle.
• Run the full test at the default 1 GB size, twice, and save or screenshot both results (AS SSD Benchmark can export results and save screenshots from its File menu).
• Compare patterns, not just totals.
• 4K-64Thrd now well above 4K on reads means queuing is working. Flat 4K-64Thrd still points to mode or driver. Weak writes only points to alignment or free space. Everything weak points back to the general low-score checklist, including port, cable and enclosure checks.

Keep those saved runs. A dated series of consistent results is how you spot real decline later, instead of arguing with a single number remembered from months ago. You can always get a fresh, verified copy of the tool from our download page if your current one has an uncertain history.

When low 4K is the drive telling the truth

If mode, alignment, space, power and background are all clean and 4K results remain far below the drive’s class across repeated quiet runs, accept the possibility that the drive is worn or failing. Very small, heavily used drives and drives that have lived nearly full for years can genuinely lose random-write pace. Back up while the drive still cooperates, and if replacement is due, choose on the strength of real 4K behaviour and capacity for your workload rather than headline sequential figures — that is the principle behind our NVMe picks. Low 4K is rarely a mystery once the header, the layout and the test conditions have each been given a fair hearing.

AS SSD Benchmark Score Too Low? A Systematic Checklist Before You Blame the SSD

Your SSD’s total score in AS SSD Benchmark has come in far below what you expected — perhaps below a screenshot of the same model online. Resist the urge to declare the drive fake or dying. Total score is a weighted summary (in the simplified formula, Read = Seq × 0.1 + 4K + 4K-64Thrd, with the 4K tests carrying the weight), so one bad setting can drag the whole number down. Work this checklist in order; most “slow SSDs” turn out to be a setting, a port or a test condition.

Before you start: back up important files on the drive you are troubleshooting. Most checks below are read-only, but the fixes that touch BIOS settings, partitions or drivers should never be attempted without a current backup.

Step 0: make the test itself fair

Before diagnosing hardware, remove the easy artefacts. Close everything that touches the disk: browsers with active downloads, cloud sync, antivirus scans, Windows Update, game launchers and any other benchmark or cloning tool. Plug laptops into mains power and set the Windows power plan to a performance-oriented profile for the test, because aggressive power saving can throttle storage between bursts. Then run the test once, note every row — Seq, 4K, 4K-64Thrd and Acc.time, for both reads and writes — and note the header line as well. A single row being low points to a specific cause; everything being low points to a systemic one.

Use the default 1 GB test size when comparing against published results, and make sure you selected the right drive if several are installed. Comparing a nearly full system drive’s score against a reviewer’s empty test-bench drive is not a comparison at all. If your first run followed these rules, keep it as your baseline and change one thing at a time from here.

Step 1: read the header — mode and alignment

The top of the window is a diagnostic in itself. If it shows pciide – BAD, the SATA controller is in IDE mode and queued 4K performance — the heart of the score — is capped before the drive gets a chance. Fixing that is a BIOS-mode job with a real boot risk if done carelessly; follow the backup-first path in our pciide – BAD guide rather than flipping the setting on impulse. If it shows alignment BAD instead (or as well), the partition layout is costing write performance; see the alignment guide and confirm the state with the alignment check.

If the header shows storahci or msahci with alignment OK, mode and layout are cleared and you move on with real information. Those two checks eliminate the most dramatic score killers in under a minute, which is exactly why AS SSD Benchmark has displayed them at the top for so long.

Step 2: interface, port and cable (SATA drives especially)

A SATA SSD can only be as fast as the port it is plugged into. On older motherboards, some SATA ports run at the earlier, slower SATA generation while others run at full speed — and cases, front-panel headers and cheap add-in cards add more slow paths. Check your motherboard or PC manual for which ports are the fastest, move the SSD to one of them, and try a different, known-good SATA data cable: damaged or very old cables cause renegotiation and errors that look exactly like a slow drive. For NVMe drives, the equivalents are slot generation and lane sharing — a slot that shares bandwidth with other devices, or an adapter in a slow slot, will cap sequential results no matter how good the drive is.

External enclosures deserve special suspicion. Benchmarking through a USB enclosure measures the bridge chip and USB link as much as the SSD, and some bridges hide the drive’s identity and features entirely. Judge a drive’s health and speed installed internally wherever possible, and treat enclosure numbers as enclosure numbers.

Step 3: free space, temperature and drive state

SSDs slow down as they fill up, particularly on writes, because the controller has less free space to work with for wear levelling and garbage collection. If the drive under test is nearly full, free space properly — move data off, empty what can be emptied — and retest before drawing conclusions. A system drive kept permanently above roughly nine-tenths full is a system drive asking for a larger replacement, not a mystery fault.

Heat matters too, mainly for NVMe drives under sustained load: a drive that starts fast and fades during the run may be thermal throttling. AS SSD Benchmark itself shows no temperature — it has no monitoring features at all — so check temperature with your drive maker’s utility or a reputable hardware monitor if you suspect heat, improve case airflow, and consider whether the drive sits under a hot graphics card. Note the pattern (fast start, slow finish) rather than chasing a single number.

Step 4: background load and Windows state

Re-test at a quiet moment: after a fresh reboot, with sync and updates paused, and nothing copying in the background. Then compare row by row with your baseline. Sequential-only slowness points back to interface, port or enclosure. 4K and 4K-64Thrd slowness with healthy sequential numbers points to mode, alignment, driver or CPU/power state — the deep dive is in our low 4K scores guide. Write-only slowness with healthy reads points to free space, write-cache policy or a drive working hard on internal housekeeping — leave the system idle for a while and test again before concluding anything.

Also remember what a fair reference is. Review scores come from specific systems, firmware and fill levels. Your score should land in the same neighbourhood for the same drive class, not match a screenshot to the digit. Geography matters less than method: same test size, same quiet conditions, same honest comparison.

When the checklist really does point at the drive

If mode is AHCI, alignment is OK, the port and cable are known-good, the drive has breathing room, the system is cool and quiet — and the score is still far below the drive’s class across several clean runs — then the drive itself becomes the likely story: heavy wear, failing flash or a controller on its way out. Back up first, while the drive still works. At that point money spent on more troubleshooting is usually wasted; put it towards a replacement chosen on capacity and interface rather than marketing peaks — our NVMe buying guide is built around AS SSD-style results rather than box claims — and re-run the tool from our download page on the new drive to establish its clean baseline. A low score is a question, and this checklist is how you make the drive — not a setting — earn the blame.

SSD Alignment BAD in AS SSD Benchmark — Impact and Safe Ways to Fix It

Beside your drive name, AS SSD Benchmark may show the alignment status in red: BAD. Unlike a low score, this is not about how fast your SSD is today — it is about how its partitions line up with the drive’s internal layout, usually a leftover from an old clone or an install created in the hard-drive era. This guide covers what misalignment actually does, how to confirm it, and the honest, backup-first choice between trying to realign in place and starting clean.

Before you start: back up important files on the drive you are troubleshooting. Most checks below are read-only, but the fixes that touch BIOS settings, partitions or drivers should never be attempted without a current backup.

What alignment BAD means

SSDs store data internally in pages and blocks that are larger than the small units operating systems historically used. For reads and writes to land efficiently, the start of each partition should line up — be aligned — with those internal boundaries. Modern Windows installations align partitions correctly by default. A BAD result usually means the partition was created by older tooling, restored from an old hard-drive image, or cloned without alignment correction, so its starting offset falls in the wrong place. AS SSD Benchmark reports that offset status at the top of its window, alongside the drive model, firmware and controller information.

Notice what the warning does not say. It does not say the SSD is failing, worn out or about to lose data. Alignment is a layout property of the partitions, not a health measurement — and AS SSD Benchmark offers no SMART or health features with which to judge the drive itself. Keep the two questions separate: layout can almost always be corrected; health, if it is genuinely poor, is a different conversation.

What misalignment costs you

When a partition is misaligned, a single logical write can straddle two physical blocks, forcing the drive to do extra read-modify-write work behind the scenes. The visible effects are slower writes — small random writes suffer most — and more write amplification than necessary, which is wasted work for the controller. Sequential large-file results may look nearly normal, which is why some misaligned systems feel “mostly fine” while their 4K write numbers disappoint.

Be wary of any page that promises an exact percentage gain from fixing alignment. The improvement depends on the drive, the workload and how bad the offset is, and no honest guide can quote your number in advance. Use our alignment check walkthrough to record the before state, fix the layout if you choose to, and let your own re-run tell the story. If scores are low for several reasons at once, alignment is only one line in the fuller low-score checklist.

Confirm it before you fix it

Back up first — before confirmation steps that change nothing, and absolutely before any fix. A full backup of important files, ideally a complete drive image on a separate physical drive, is the price of admission for partition work. Then confirm the finding: re-run AS SSD Benchmark with the correct drive selected and note the exact offset/alignment line, and cross-check the partition starting offset in Windows’ system information or disk tools. If two views agree the partition is misaligned, you have a real target. If they disagree, resolve the disagreement before touching the layout.

Also record the companion facts while you are there: which controller label the header shows (a system can be misaligned and in IDE mode at the same time — see pciide – BAD), how full the drive is, and whether this Windows install is a fresh build or a clone from an old hard drive. Cloned-from-HDD installs are the classic alignment cases, and knowing the history helps you pick the fix below.

Your three honest options

Option one: leave it alone. If the machine is a secondary system, the drive is nearly full and due for replacement anyway, or the performance you have is acceptable for how the PC is used, living with misalignment is a defensible choice. It is a performance and efficiency issue, not a ticking bomb.

Option two: realign in place with a partition tool. Several partition utilities advertise alignment correction without a reinstall. That can work — but no tool can honestly promise a lossless outcome on your specific system. Power loss, a tool bug or an unexpected layout can damage the partition table, which is why the backup is not optional and why you should use a reputable tool, follow its own alignment workflow exactly, and never run it on a laptop battery that might die mid-operation. This site does not guarantee any tool’s result; if the data matters more than the downtime, choose option three.

Option three: clean reinstall or fresh clone with correct alignment. Back up, then install Windows fresh onto the SSD (letting the installer create the partitions guarantees modern alignment) or re-clone using a current cloning workflow that aligns partitions for SSDs. This is the most predictable path and the best moment to do it is when you were already planning a new drive or a clean start — see the workflow in cloning your OS drive to an SSD. It costs the most time and gives the cleanest result, with no in-place partition surgery to worry about afterwards.

After the fix: verify like a sceptic

Whichever path you took, verify rather than assume. Open AS SSD Benchmark — from the verified copy on our download page if you reinstalled — reselect the drive and confirm the header now shows alignment OK. Then run a clean full test with no other disk-heavy work running and the default 1 GB test size, and compare Seq, 4K and 4K-64Thrd against the numbers you recorded before. Writes and 4K writes are where an alignment fix most often shows itself.

If the header still says BAD, do not stack another tool on top of the first attempt. Restore from your backup if the system behaves oddly, and reconsider the clean-install path with fresh eyes. Two failed in-place attempts are information: the layout on that drive is not a good candidate for surgery.

When the real problem is the drive, not the layout

Occasionally alignment BAD is discovered on a drive that is also old, tiny by modern standards or showing unrelated errors in daily use. Fixing the layout will not restore worn flash or repair a failing controller. If Windows reports read errors, files corrupt, or the drive disappears intermittently, stop optimising: back up immediately, treat the drive as untrusted, and replace it. A correctly aligned new SSD, set up once with a clean install or aligned clone, leaves both problems behind. Alignment BAD on an otherwise healthy drive, though, is one of the most fixable findings in AS SSD Benchmark — confirm it, back up, pick the path that matches your risk tolerance, and verify the OK with your own eyes.

storahci and msahci in AS SSD Benchmark Explained — When the Top-Line Label Matters

Next to your drive name at the top of the AS SSD Benchmark window there is a short driver label — storahci, msahci, pciide or a vendor name — and sometimes a coloured OK or BAD beside it. Many guides treat every unfamiliar label as a warning. It is not. This page explains what storahci and msahci each mean, which top-line states are completely normal, and the few that genuinely deserve action.

Before you start: back up important files on the drive you are troubleshooting. Most checks below are read-only, but the fixes that touch BIOS settings, partitions or drivers should never be attempted without a current backup.

Where the label comes from

The header area of AS SSD Benchmark shows the selected drive’s model and firmware, its capacity, the storage driver Windows is using for it, and the partition alignment status. That header is the source of the best-known AS SSD warnings — pciide – BAD for IDE mode and alignment BAD for a misaligned partition — as covered in the AS SSD feature descriptions recorded in our fact baseline. The driver word itself is simply a report, not a grade: storahci and msahci both mean the drive is running in AHCI mode, which is what a SATA SSD wants.

Understanding that saves a lot of unnecessary “fixing.” A system showing storahci is not broken, a system showing msahci is not automatically outdated in a way that harms the drive, and neither label needs to be chased away with a driver package downloaded from a forum. The labels worth acting on are the mode problems — IDE instead of AHCI, or a vendor RAID driver doing something unexpected — not the choice between Microsoft’s two AHCI driver generations.

storahci vs msahci: the actual difference

msahci is Microsoft’s older AHCI miniport driver, familiar from the Windows 7 era. storahci is its successor, Microsoft’s StorPort-based AHCI driver used by newer Windows versions. Both drive the same AHCI controller mode and both support the queuing behaviour an SSD needs for strong 4K-64Thrd results. In everyday benchmarking, two otherwise identical systems — one on msahci, one on storahci — should land in the same performance neighbourhood. Small run-to-run differences are normal and are not evidence that one driver is “wrong.”

You will also sometimes see a vendor AHCI or RAID driver name instead, for example from Intel or AMD, when the chipset maker’s driver is installed. That too can be entirely normal. Vendor drivers can offer their own power or RAID features, and Microsoft drivers offer simplicity and predictable updates through Windows. There is no universal winner, and swapping drivers purely because a screenshot online showed a different word is not troubleshooting — it is churn, with a small but real risk of a boot problem if the change goes wrong.

What is normal, and what is worth handling

• Normal — storahci with an OK alignment note.
• This is the expected state on a modern Windows install with a SATA SSD. Nothing to do.
• Normal — msahci on an older Windows installation.
• AHCI is active; the driver is simply the older Microsoft one for that OS generation. Nothing to do unless you have a separate, specific reason.
• Normal — a vendor AHCI driver name with healthy scores.
• If sequential and 4K results match the drive’s class and the system is stable, leave it alone.
• Worth handling — pciide – BAD.
• The controller is in IDE mode. That one does suppress queued performance. See the cautious switching guide at pciide – BAD — and note its backup and boot-risk warnings before changing BIOS settings.
• Worth handling — alignment BAD alongside any driver label.
• Alignment is independent of the driver word. A storahci system can still be misaligned. See alignment BAD explained and verify with our alignment check walkthrough.
• Worth a look — the label or mode changed unexpectedly after a BIOS reset or hardware change.
• BIOS updates and resets can revert SATA mode. If scores dropped at the same time, check the mode first.

How to confirm the driver without changing anything

If you want to verify what Windows thinks is installed, open Device Manager and look under IDE ATA/ATAPI controllers or Storage controllers. The AHCI controller entry there corresponds to the mode AS SSD Benchmark reports. You can view the driver provider and date in the entry’s properties. Treat this as a read-only inspection: viewing is safe, while “Update driver” experiments, manual INF installs and registry edits are changes — and changes to storage drivers deserve the same respect as BIOS changes, including a current backup and a note of what was there before.

A cleaner confirmation is comparative. Run AS SSD Benchmark, note the top line, then check the scores themselves. If the drive shows storahci or msahci, alignment OK, and 4K-64Thrd scores in line with the drive’s class, the header is telling you the setup is healthy whatever word it uses. Our low-score checklist helps you judge that “in line” part systematically instead of by gut feeling, and the AHCI vs IDE guide shows how to check the mode for every drive, not just the system drive.

Driver updates: the cautious position

Storage drivers are not like graphics drivers. Newer is not automatically faster, release notes rarely promise benchmark gains, and a bad storage-driver change can affect booting — the worst possible trade for a hypothetical few points. Update a storage driver when there is a concrete reason: a known bug affecting your controller, a Windows upgrade that requires it, or a vendor advisory for your exact hardware. Get the package from your PC or motherboard maker, or from the chipset vendor — never from a driver-aggregator site — and back up first.

Do not, under any circumstances, follow old forum advice to force a different AHCI driver through registry edits just to change the word in the AS SSD header. The header word is information. pciide is the only common label that signals a mode genuinely worth fixing, and even that fix lives in BIOS mode preparation, not in registry driver swaps.

The short version to remember

storahci: good, modern Microsoft AHCI driver. msahci: good, older Microsoft AHCI driver. Vendor AHCI name: usually fine. pciide – BAD: IDE mode — the real warning, fixable with preparation and care. Alignment BAD: a separate, real warning with its own fix path. If your header shows an AHCI driver and OK alignment, close the troubleshooting tabs, run a clean benchmark from our verified download copy, and judge the drive by its scores and by how the system feels — not by which of two good driver names Windows happens to use.

pciide – BAD in AS SSD Benchmark: What It Means and How to Switch to AHCI Safely

In the top-left corner of the AS SSD Benchmark window, in red, you may see “pciide – BAD.” It looks alarming, and many people discover it only after wondering why a new SSD scores far below expectations. This guide explains what pciide – BAD actually means, what IDE mode costs an SSD, and — with the risks stated plainly — the general path for switching a system to AHCI without turning a performance tweak into an unbootable PC.

Before you start: back up important files on the drive you are troubleshooting. Most checks below are read-only, but the fixes that touch BIOS settings, partitions or drivers should never be attempted without a current backup.

What pciide – BAD is telling you

The text at the top of the AS SSD Benchmark window reports which storage driver and mode the selected drive is running under. “pciide” is the generic IDE driver. When you see pciide – BAD, your SATA controller is operating in IDE (legacy) mode rather than AHCI mode. The “BAD” is the program’s blunt assessment for an SSD: IDE mode was designed for older hard drives and does not expose the features a modern SSD expects.

The practical cost is concentrated in queued random work. AS SSD Benchmark’s 4K-64Thrd test spreads reads and writes across 64 threads, a pattern that benefits from Native Command Queuing (NCQ), which AHCI provides and IDE mode does not. Sequential scores may look almost respectable in IDE mode while 4K-64Thrd — and therefore the total score, which weights the 4K tests heavily — lags badly. Our explainer on storahci and msahci labels covers the AHCI-side driver names you should see instead once the mode is correct.

Before you touch anything: backup and honest assessment

Stop here and back up. Switching the SATA mode of the controller that hosts your Windows system drive is one of the classic ways to make Windows fail to boot, because Windows loads a different storage driver depending on the mode it finds at startup. If the mode changes before Windows is prepared for it, the machine can blue-screen during boot until the setting is changed back. That risk is manageable, but only if you prepare for it.

• Make a full backup of important files — ideally a complete image of the system drive, stored on a different physical drive.
• Write down your current BIOS/UEFI SATA mode before changing it, so you can restore exactly that value if Windows will not start.
• Confirm you know how to enter your BIOS/UEFI setup (the key is shown during boot on most systems, commonly Del or F2) and that you can do it without Windows.
• Check whether you actually need the switch.
• If this is a secondary data drive on an old system that otherwise works, leaving it in IDE mode is a legitimate choice. The switch matters most for a Windows system SSD whose 4K performance you use every day.
• Read our AHCI vs IDE check guide first if you are not yet sure which mode each drive is using.

If any of that makes you uncomfortable, the safest “fix” is to do nothing until you can set aside time and a backup drive. pciide – BAD is a performance warning, not an emergency, and your data is worth more than the score difference.

The general switching path (high level, with caution)

Caution: the steps below are a general outline, not a script for your specific motherboard and Windows installation. Menu names and locations vary by vendor, and the Windows-side preparation differs between installations. If a step does not match what you see on your system, stop and look up your motherboard or PC model’s own documentation rather than guessing.

In outline, a safe mode change always has the same shape. First, while Windows still boots normally in the current mode, you prepare Windows so that the AHCI driver is available at the next startup — on modern Windows this preparation is the step people most often skip, and skipping it is what causes the boot failure. Second, you restart into BIOS/UEFI setup, find the SATA configuration for the relevant controller (often labelled SATA Mode, SATA Operation or Configure SATA As), and change IDE to AHCI. Third, you save, exit and let Windows boot, allowing it extra time on the first AHCI start while it detects the controller under the new mode. Fourth, once Windows is stable, you re-run AS SSD Benchmark and confirm the top line now shows an AHCI driver such as storahci or msahci instead of pciide, then compare the 4K-64Thrd result.

Do not change settings for controllers your system drive is not attached to, do not switch a system into RAID mode as a shortcut unless it was already using RAID, and never update the BIOS itself as part of this job — that is a separate procedure with its own risk and its own backup requirements.

If Windows will not boot after the switch

Do not panic and do not reinstall anything yet. Re-enter BIOS/UEFI setup and set the SATA mode back to the value you wrote down (IDE). In most cases Windows will then boot exactly as before, because you have simply restored the environment its current driver setup expects. That recovery path is the reason the “write it down first” step matters. Only troubleshoot the AHCI preparation again once the system is back up, your backup is verified, and you have time to work carefully.

If the system still will not boot after restoring the original mode, the problem is likely something else that changed in the same session — a boot-order change, a different controller being altered, or an unrelated failure. Restore any other setting you touched, and seek model-specific help with your notes in hand rather than changing more settings at random.

After a successful switch: verify, do not just celebrate

Re-run the full test from a clean state: no other disk-heavy programs running, the drive selected correctly, and the default 1 GB test size for comparability. Expect the clearest change in 4K-64Thrd and in the total score; sequential numbers may move only slightly, which is normal. If pciide – BAD is gone but scores are still disappointing, work through the broader checklist in our low-score troubleshooting guide, and check the second classic top-line warning — alignment — in our alignment BAD guide. Mode and alignment are separate settings and either one can hold a drive back on its own.

Finally, keep perspective. AHCI is the right mode for a SATA SSD and fixing pciide – BAD is worthwhile on a system you use daily. But if the machine is very old, the drive itself is near the end of its life, or you were already planning an upgrade, putting the effort into a clean move to a new SSD may serve you better than perfecting the old setup. Decide with your backup in place and your original BIOS value on paper, and the switch stops being scary — it becomes a reversible, half-hour job with a clear payoff in the benchmark and in everyday responsiveness.

“Could Not Open Physical Device” in AS SSD Benchmark — What It Means and How to Fix It

You select your SSD, press Start, and instead of a benchmark you get a short message: “Could not open physical device.” Nothing is measured, no score appears, and the program gives you almost no extra detail. This guide explains what that message actually means, why it was a known bug in older builds, and the safe order in which to check your system — starting with your version number, not with system changes.

Before you start: back up important files on the drive you are troubleshooting. Most checks below are read-only, but the fixes that touch BIOS settings, partitions or drivers should never be attempted without a current backup.

What the message means

AS SSD Benchmark does not only read files on a volume. To measure sequential, 4K and access-time performance without the operating system cache distorting the result, it needs direct, low-level access to the physical drive behind the drive letter you selected. “Could not open physical device” means Windows refused that access, or the program failed while trying to obtain it. The drive itself is not automatically faulty — in most cases the block happens at the permission, driver or software level before any test data is written.

That distinction matters. A failed open is not a bad score and it is not a health verdict. AS SSD Benchmark has no SMART, health or temperature features, so this message tells you nothing about wear or remaining life. It only tells you the test could not start in the way the program needs. Treat it as an access problem first, and only consider hardware after the software causes below have been ruled out.

First check: are you on the final version?

Before changing anything, confirm which build you are running. The current and final version is 2.0.7316.34247, built in January 2020. According to the version notes recorded by Softpedia, the one confirmed change in that final build is exactly this point: Bugfix “Could not open physical device.” In other words, if you are running an older 2.0 or 1.x build, this error may simply be the old bug, and updating is the correct first fix — not a registry edit or a driver change.

If your copy came from an old download folder, a forum attachment or a software archive, replace it with a fresh copy from the official file. Our download page links to the official alex-is.de file and lists the verified SHA-256 hash so you can confirm the package is intact. Extract the ZIP fully before running it, and keep the AS SSD Benchmark.exe file together with its en-US language folder in the same directory — running the exe alone from inside the ZIP or from a different folder causes separate startup problems covered in our guide to AS SSD Benchmark not starting.

Back up first, then work through the access checks

Benchmarking is normally non-destructive, but troubleshooting is not the moment to take chances. Back up anything important on the drive before you start changing permissions, drivers or controller settings. Then work through these checks in order, retesting after each one rather than changing several things at once.

• Run as administrator.
• Close AS SSD Benchmark completely, right-click the exe and choose Run as administrator. Direct device access is exactly the kind of operation Windows may deny to a standard session, and this single step resolves many cases.
• Close other disk tools.
• Quit drive utilities, cloning tools, backup jobs and other benchmarks that may be holding the drive open, then try again. A drive that is actively being imaged or scanned may refuse a second low-level handle.
• Check security software.
• Antivirus and endpoint tools sometimes block direct disk access by unfamiliar portable programs. Note any prompt or log entry instead of disabling protection wholesale; if your security tool offers an allow prompt, use it only for the verified official file.
• Confirm the drive is online.
• Open Windows Disk Management and make sure the disk and volume show as online and healthy there. If Windows itself cannot open the volume normally, fix that first — AS SSD Benchmark will not succeed where the operating system is already struggling.
• Try a different target.
• If the program offers another connected drive, run a short test on that drive. If the other drive works, the problem is specific to the first drive, its driver or its connection. If no drive works, the problem is more likely permissions or the program copy itself.

Controller mode and driver context

Look at the top of the AS SSD Benchmark window once it opens. That area shows the drive model, firmware, controller information and partition alignment status — the same area behind warnings such as pciide – BAD. The display does not cause the open error, but it is useful context: a very old storage driver, an unusual RAID or virtual-disk arrangement, or a drive presented through a USB bridge can all change how direct access behaves. For background on those top-line labels, see our guide to checking AHCI vs IDE mode and the companion fix for pciide – BAD. Do not switch controller modes just to chase this error — mode changes carry a real boot risk and are covered, with warnings, in that pciide guide.

Also be honest about the environment. AS SSD Benchmark is a Windows desktop tool from 2020. Running it inside a virtual machine, through a remote session with restricted device access, or against a network or virtual disk may fail simply because the “physical device” the program expects is not exposed in the usual way. That outcome has not been separately verified for every hypervisor or configuration, so treat VM results as “test it on your setup” rather than as a guaranteed yes or no.

What not to do

Do not download “fixed” executables from random forums, do not replace system storage drivers with packages meant for a different chipset, and do not edit the registry on the strength of an old forum post without understanding exactly which key is involved and how to reverse it. Storage-driver and registry mistakes are one of the few ways a simple benchmark problem can turn into a system that no longer boots. Every step in this guide is reversible; keep it that way.

Equally, do not keep re-running the test dozens of times hoping it will pass. If the error is consistent after the version check, the administrator test and the close-other-tools test, you have useful information: the block is systematic. Note the exact version, the drive model shown in the window, and what you already tried — that record is worth more than another ten attempts.

When the drive itself becomes the suspect

Suspect the drive or its connection only after the software path is clean: final version, administrator session, no competing disk tool, and the drive visible and usable in Windows. Then check the basics — reseat or replace a SATA data cable where practical, try a different SATA port, and confirm the drive works normally for ordinary file copies. If Windows itself reports errors reading the drive, back up immediately and stop benchmarking: repeated full tests add load to a drive you may need for recovery.

If the drive is old, small or already showing problems in everyday use, a new SSD may be the practical answer — but use the error as a prompt to verify, not as proof. Once access works again you can benchmark the replacement properly and, if you are moving an existing Windows install, follow a careful cloning workflow rather than copying files by hand. Start from a clean, verified copy of the tool, work the checks in order, and this historically buggy error is usually either gone with the final version or explained by a permission you can fix in minutes.