Check the TRIM setting

TRIM allows for the improvement in the writing of data to the SSD as well as contribute to a longer SSD life. You should make sure that this setting is enabled.

• In the search bar type cmd
• Right-click Command Prompt and click Open as Administrator
• Type fsutil behavior query DisableDeleteNotify and press Enter
• If you get 0 as a result, it means TRIM is already enabled. If you get 1, please make sure you follow the next steps
• Type fsutil behavior set DisableDeleteNotify 0 then press enter.

Check if the problem still occurs.

Optimize the drivers

If your SSD drive is not optimized then this can cause the slow SSD problem.

• Click Start and in the search bar type Defragment and Optimize Drives
• Click Defragment and Optimize Drives
• Highlight your SSD and click on Optimize

Check if the slow SSD issue still occurs.

Make sure AHCI Mode is enabled

• Open Device Manager
• Expand the IDE ATA / ATAPI Controllers
• If you see AHCI Controller in the list, you have it enabled. In case you see only ATA and IDE words you are likely to have AHCI disabled on your computer

If it is disabled then you will have to enable it.

• Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStorV and set the value named Start to 0
• Find the key KEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStorAVC\StartOverride and set 0 to 0
• Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci and set Start to 0
• Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci\StartOverride and set 0 to 0
• Restart your computer
• Go to UEFI/BIOS firmware settings, enable AHCI mode, save and exit
• Restart your computer

Check if you are still experiencing the same issue.

Change the boot order from HDD to SSD

• Restart your Windows 10 computer and boot into BIOS
• Make sure to change the boot sequence of HDD and SSD by giving first priority to SSD

Check if the issue still persists.

Update the firmware to improve performance

You should check the SSD manufacturer website for any updates to your particular SSD model firmware. If an update is available then you should download and install it. Check if you are still experiencing a slow SSD issue.

Optimize the SSD to reduce boot time

• Search for Disk Cleanup in the search bar.
• Select the SSD drive and click OK to launch the process
• Delete the detected junk files
• In the Start menu search for defrag and open Defragment and Optimize Drives
• Select the SSD drive and click the Optimize button

Try to check if this fixes the problem.

Scan your computer for viruses and malware

Use Windows Security To Fix Slow SSD

• Search for “Windows Security” in the Start menu and launch the app.
• Click “Virus & threat protection”.
• Press the “Quick scan” button and wait for the scan to complete.
• Once the scan has been completed, the “Current threats” screen will display the outcome of the scan. If threats were found, you’ll be able to get their details using the “Threat history” button.
• If the quick scan doesn’t find any problems, you can run a more thorough check by clicking the “Scan options” link. Here, you can choose to run a “Full scan” which will check every single file, as well as any running programs.

Use Malwarebytes To Fix Slow SSD

• Go to https://www.malwarebytes.com/antimalware/.
• Download the free version.
• Save the installation file to your Windows computer.
• After the download is complete, double-click the file to begin installing Malwarebytes.
• Follow the instructions on the installation screen. Make sure Enable free trial of Malwarebytes Anti-Malware PRO is unchecked.
• Make sure the computer is connected to the Internet.
• Open Malwarebytes.
• Malwarebytes will generally prompt you to download and install any available updates when you open the program. To check for and install updates manually, click the Update tab, then click Check for Updates.
• On Malwarebytes’ Anti-Malware screen, click the Scanner tab. The Scanner window will open.
• On the Scanner window, select one of the first two options: Perform quick scan which is  recommended in most cases or Perform full scan which is selected if a quick scan has not solved your problem.
• If Malwarebytes detects a threat, it will place the suspicious file in quarantine. After the scan is complete, click the Quarantine tab and review the threats Malwarebytes detected: To permanently delete a malware program, select its name and click Delete.
• After the scan is complete and you have addressed any threats placed in quarantine, click Exit to close Malwarebytes.