Question WD SN550 1TB low speed

[datbi201]

Hi there,
I have 02 ssd WD Blue SN550 1TB both of which have TBW relative high 500 over 600 TB as said by manufacturer. However I think high TBW is NOT a cause of my following issue.

• My desktop: i5 9400 + Giga B360M with 01 USB 3.1 Gen2 port + 2x8GB Adata
• 01 SSD ported to M.2 PCIe Gen3 x4 (disk A) - system partition.
• 01 SSD ported to M.2 PCIe Gen 3 x2/Sata (disk B) (lower speed interface)

I tested 2 disks and the speed is as it shoud.

However when I copied file (movies or ISO file, GBs size), the transfer tests are so lower than expected, especially speed from PCIex4 to PCIex2

I also tested "internal copy" (same disk copy)

I installed disk B into Orico NVME-usb with 10 Gbps speed and plug to USB 3.1 Gen 2 (10 Gbps). The test speed by CrystalDiskMark looks good (max speed of usb gen 2 port) but the copy speed so low ~50 MB/s. At least the speed seem to be constantly low.

Any advice?
Is low health status affect the performance? what wrong with my ssd or my box or smt?
Thanks guys

 

[datbi201]

Sorry guys, i found out the cause of this issue.
I set "compress file to save disk" in the partition properties so system have to compress files prior to write them into disk making low speed.

The issue was fixed completely.