Question M.2 NVMe SSD has slower read/write speeds than before ?

[NJMODS]

My 250gb NVMe SSD (1 year old) has slower read/write speeds after I revert from Windows 11 to Windows 10.

Before - Read: 1600mb/s, Write: 1200mb/s
After - Read: 650mb/s, Write: 250mb/s

I have cleaned installed Windows 10 afterwards but still the speed is same.
BIOS is updated
Controller mode is AHCI (There are only to modes available RST and AHCI in BIOS)
Regularly TRIMMED.

But there is still no solution, I've tried to post this query on other forums and reddit but still there were no response

 

[COLGeek]

What are the complete specs for this system (make/model of ALL installed components)?

 

[NJMODS]

What are the complete specs for this system (make/model of ALL installed components)?

It's a Lenovo L340-15IRH Laptop with

Laptop:
Intel Core i5-9300HF 2.4GHZ
NVIDIA GTX 1050 3GB
8GB RAM
WD BLUE 1TB HDD

Installed Separately:
ADATA SWORDFISH NVMe 250GB (Windows)

ADATA SWORDFISH:
Storage: 250GB
Transfer Mode: PCIe 3.0 x4
NVM Express 1.3
Firmware Updated to Latest version
It has features of SMART, TRIM and VolatileWriteCache

 

[COLGeek]

Is Windows installed on the SSD or the HDD? Why did you revert from Win 11 to 10?

After installing Win 10, did you update all drivers (video, network, motherboard chipset, etc)?

https://www.intel.com/content/www/us/en/support/detect.html

 

[NJMODS]

Is Windows installed on the SSD or the HDD? Why did you revert from Win 11 to 10?

After installing Win 10, did you update all drivers (video, network, motherboard chipset, etc)?

https://www.intel.com/content/www/us/en/support/detect.html

Windows is installed on SSD, I revert back to Windows 10 is because Windows 11 still needed some optimizations. And after installing windows 10 I've updated all drivers and firmware.