If you’ve migrated your operating system from a mechanical hard drive to a solid-state drive, the partitions may not be properly aligned. This could result in slower performance, which you can fix by re-aligning them.

What Is Partition Alignment, and Why Should I Care?

A typical mechanical hard drive generally starts its first partition after 63 empty blocks, while a solid-state drive starts its first partition after 64 empty blocks.

The Windows installer knows how to handle this properly, so most people shouldn’t have a problem. If you bought a computer that came with Windows installed on an SSD, your partitions should be correctly aligned. If you installed Windows on your SSD from scratch, your partitions should be correctly aligned. The installer does it all automatically.

However, if you migrated an existing Windows installation from an old mechanical hard drive to a solid state drive, the software may not have accounted for this. Some do, some don’t. If it didn’t, your partitions won’t be correctly aligned, and which can slow down your SSD. How much slower performance depends on your specific SSD.

Thankfully, there’s a quick way to check whether your partitions have this problem and fix it if they do.

How to Check if Your Partitions Are Correctly Aligned

You can check this very easily from the System Information tool. To launch it, open your Start menu, type “msinfo32”, and press Enter to launch the System Information tool. You can also press Windows+R on your keyboard, type “msinfo32” into the Run dialog, and press Enter.

Head to Components > Storage > Disks. Scroll down in the left pane, locate your SSD, and find the “Partition Starting Offset” value below it. There will be a different partition starting offset value for each partition on the drive.

Check if this number is evenly divisible by 4096. If it is, the partition is correctly aligned. If it isn’t, the partition isn’t correctly aligned.

For example, for the number above, we’d do this math:

1048576 / 4096 = 256

There’s no decimal remainder, so the number is evenly divisible. That means the sectors are correctly aligned. If we did the math and found a decimal remainder (e.g. 256.325), that would mean the numbers aren’t evenly divisible, and the sectors aren’t correctly aligned.

How to Fix Incorrectly Aligned Partitions

 If you find that your partitions are incorrectly aligned, you can fix them and hopefully get a nice speed boost.

While you could just reinstall Windows and have it partition your drives from scratch, you don’t have to do that. Quite a few partition managers can realign your partitions for you. However, this often involves some complex fiddling.

While this shouldn’t cause any problems, it’s always a good idea to have backups of your important data–especially when messing with your computer’s partitions.

The fastest way we’ve found to do this is to use the free version of MiniTool Partition Wizard–you don’t need to pay for a premium version, the free version can do everything you need. Install it on Windows, launch the partition manager, right-click the partition you want to align, and select “Align”. It’ll do all the hard work for you.

When you’re done, you should hopefully find that you’re getting the best possible speeds out of that blazing fast SSD.