Check SSD Alignment in AS SSD Benchmark: OK vs BAD

Near the top of the AS SSD Benchmark window, next to the drive model and controller information, there is a small alignment indicator that many users ignore until a forum post tells them it says BAD in red. That indicator is one of the most useful free checks in the whole tool. This guide explains what partition alignment means in plain terms, how to check it in seconds using the top information area, what OK and BAD actually signify, and what to do next if yours is wrong. The focus here is checking and understanding; the fix itself has its own dedicated guide.

You do not need to run a full benchmark to check alignment. Open the tool from the download page package, select the drive, and read the top area. If you are completely new to the window layout, skim how to use AS SSD Benchmark first so the top information, result rows, and menus are familiar.

What partition alignment means

Your SSD stores data in physical blocks, and your Windows partition starts at a specific offset on the drive. Alignment describes whether that starting offset lines up neatly with the physical block boundaries underneath. When the partition is aligned, each logical block Windows writes maps cleanly onto the physical storage. When it is misaligned, writes can straddle boundaries, forcing the drive to do extra work behind the scenes: reading and rewriting more than the operating system asked for.

This mattered most in the era when systems were upgraded from hard drives, cloned from old installations, or set up with older partitioning tools that chose starting offsets suited to spinning disks rather than flash storage. A fresh, modern Windows installation on an SSD normally creates aligned partitions automatically, which is why most users today will see OK and never need to think about this again. Misalignment still appears on cloned systems, restored images, and drives partitioned years ago, which is exactly why a ten-second check is worthwhile after any migration.

How to check alignment in AS SSD Benchmark

Start the program and select the SSD in the drive drop-down at the top. Look at the information block beneath the drop-down. Among the model, firmware, controller, and capacity lines you will find the alignment status for the selected partition, shown together with its offset value. The tool expresses the result in the clearest possible way: a green OK when the offset divides correctly, or a red BAD when it does not.

• Select each SSD partition letter in turn if the drive has several; check the system partition especially.
• Read the status word itself, OK or BAD, rather than trying to judge the raw offset number by eye.
• Note the controller line at the same time; alignment and controller mode are the two classic top-area warnings, and they are checked together for a reason.
• Take a screenshot of the window if you are going to ask for help, so the exact offset and status are visible.

That is the entire check. No test file is written, no score is needed, and it works before you benchmark at all. If you see OK, alignment is not your problem and you should look elsewhere for any slowness. If you see BAD, you have found a real, fixable issue, and it is worth fixing before you judge the drive’s benchmark scores, because misalignment taxes exactly the small random writes that Windows performs all day.

What OK means, and what BAD costs you

OK means the partition offset aligns with the drive’s physical layout. Writes proceed without the extra boundary-crossing penalty. It does not guarantee the drive is fast or healthy; it removes one specific handicap so the other numbers in the window can be judged fairly.

BAD means the partition is misaligned. The practical costs are slower random write performance, extra write work for the drive, and benchmark results, particularly in the 4K write row, that undersell what the hardware could do if it were set up correctly. The drive is not necessarily damaged, and your data is not necessarily in danger, but the configuration is wrong and every day of use pays a small tax for it. This is a configuration problem, not a reason to replace the SSD.

Why misalignment happens

The usual stories are cloning an old system from a hard drive to an SSD with tools or settings from the hard-drive era, restoring an old disk image onto new hardware, creating partitions with outdated utilities, or dual-boot and multi-system setups built over many years. In each case the system works, Windows boots, and nothing looks broken, which is why misalignment survives unnoticed until someone runs a tool that displays it. AS SSD Benchmark displays it for free at the top of its main window, one reason it remains a standard first check in SSD troubleshooting threads.

What to do if yours says BAD

First, do not panic and do not benchmark repeatedly hoping it changes; the status will not heal itself. Second, back up anything important on the drive, because any partition adjustment carries some risk if it is interrupted. Third, follow the step-by-step repair walkthrough in fixing an SSD alignment BAD warning, which covers the options from alignment tools to the clean-install route and how to verify OK afterwards. That guide assumes you have already confirmed BAD using the check on this page.

Finally, re-check with AS SSD Benchmark after any fix and run a fresh benchmark. Your 4K and total results should now represent the drive fairly, and you can compare them with your earlier screenshot to see what the handicap was costing. While you are in the top information area, also read the controller line using our guide to checking AHCI vs IDE mode, since a cloned older system that is misaligned sometimes also carries a legacy controller setting.

In short: look at the top of the window, read OK or BAD, and believe it. OK needs no action. BAD is a real configuration fault worth backing up and fixing properly, not a failing drive. Ten seconds in AS SSD Benchmark tells you which situation you are in, and that clarity is why this small indicator is checked before almost every serious SSD speed investigation.