By Emily / Last Updated February 21, 2019

"SanDisk SSD running slow!"

I just bought a new 120GB SanDisk SSD to replace the 32GB crucial one which died on me recently. I made a fresh install of windows 10, but this new SSD is shockingly slow, sometimes even slower than my HDD and sometimes even freezing. So I'm wondering if this is at all normal for SanDisk drives? If not, I'd be hugely appreciative of any suggestions/ideas/fixes! Thanks in advance :)

"I just got a Sandisk SSD PLUS 240GB, and i cant figure out why its write speeds are so low, my read speeds reach 500 MB/s and stay at that speed but write speeds reach 100mb/s... sometimes it goes to 200mb/s but quickly goes down to 100mb/s. I just cant seem to figure this out, first time owning an SSD btw"

How to fix “SanDisk SSD slow” issue in Windows 10/8/7?

Compared with traditional HDD, SSD drive is much faster in write and read speed. So many users clone operating system from HDD to SSD for a better boot experience. But sometimes SSD drives may become very slow to respond especially when the drive is almost full. If you are experiencing SanDisk or other branded SSD slowing down in Windows 7/8/10, what will you do next? Buy a new SSD or fix it? Obviously, the latter one is a much wiser and cost-effective choice. So we bring some solutions to improve SSD performance or restore it to its peak performance.

1. Quick solutions

Some default setting of the SSD in Windows might lead to the slow SSD, so first try to change the SSD setting to check if the problem can be fixed.

  • Disable Hibernation

Hibernate (or we call it Sleep Mode) is quite useful to HDD since it allows the disk to load program faster than booting system, but it is not necessary for SSD drives since its boot speed and time is already satisfactory. And the Hiberfil.sys file almost take a same amount of space as the random access memory (RAM). So it is better to disable it to free up disk space during SanDisk SSD slow.

To disable Hibernation, enter the Command Prompt window by clicking the Start button and type cmd (please run as administrator), and type command powercfg.exe /hibernate off and press Enter.

  • Make SATA controller runs in AHCI mode

AHCI (Advanced Host Controller Interface) Mode does a fabulous job of keeping the high performance of SanDisk solid state drive. So when it is disabled, the SSD might run slow and take a very long time to respond. It is better to set your SSD mode from IDE to AHCI.

1) Press WIN+R and type msconfig and then press Enter.

2) Under Boot tab, tick Safe boot, click OK to save the changes, and reboot your computer into safe mode by constantly pressing F2 or DEL (the key to press varies between systems). Change your SATA mode from IDE to AHCI. Then save settings to exit and reboot.

3) Windows will boot in safe mode this time. Run msconfig again, and untick Safe boot option Boot tab under and restart your computer.

Safe Boot

2. Advanced solutions

To fix SanDisk SSD running slow problem in Windows 10/8/7, you can use AOMEI Partition Assistant Pro. It is an all-in-one partition manager and magic disk management software for Windows 10, Windows 8.1/8, Windows 7, Windows Vista and XP. You can rely on it to optimize the SSD via several different ways.

  • Aligning SSD partition to improve the performance

Partition alignment is a new concept of SSD. It plays an important role in improving its data writing and reading speed. AOMEI Partition Assistant Pro could allow you to check whether SSD partitions are aligned, and enable you to realize partition 4K alignment easily.

1) Install and launch the software, right click the SanDisk SSD partition and choose Advanced -> Partition Alignment.

Partition Alignment

2) In the mini window, you can set partition 4K alignment. And click OK to continue.

Partition 4k Alignment

3) Finally, click Apply to save changes.

Apply Alignment

  • Secure erase SanDisk SSD to restore its peak performance

After using SanDisk SSD for a long time, it will hold a large amount of data, which could also make the SSD performance drop significantly. So erasing the data on the SSD is another effective way to optimize its performance, and you can also realize it via the AOMEI Partition Assistant Pro because it offers “SSD Secure Erase Wizard”. Please back up data on SSD in advance to avoid any data loss.

Note: This feature could only work in Windows 7, so firstly please connect the your SSD to a computer running Windows 7 and make sure it is detected successfully.

Then run the software on your computer, right click the SSD, select SSD Secure Erase, and then follow the hints to finish the operation.

SSD Secure Erase

More tips you may want to know

As an excellent SSD optimization tool, AOMEI Partition Assistant offers the easiest and most effective methods for users to tackle with“SanDisk SSD slow” issue. But in order to keep the SanDisk in a good performance and avoid such problems, it is highly recommended to take some precautionary measures like running CHKDSK to check bad sectors, performing a Disk Cleanup regularly, etc.