SN850 1TB x2- very low IOPS reported (1/3 of expected) when benching

Hi all,

I have two SN850 1TBs. One is installed to a PCH M2 slot, one to CPU M2 slot.

Both are reporting IOPS at around a third of expected.

I have a 980 Pro on another PCH M2 slot and that’s reporting better. Through Samsung Magician, that’s reporting almost 950k Random Read, 916k Random Write. The SN850s using the same app, a third of that and consistently so.

980 Pro


Sequential Read and Write are as expected.

One SN850 has 785GB free, the other 90GB free, out of 1TB per.

Running on MSI MEG X570 Godlike on BIOS 1.D3 (not the latest BIOS, I know).

Any ideas?

Edit: Updated to BIOS 1.F4, no change.

Edit: Added screenshots of results.

Hi @SlowNVME850,

Please refer below link to help you with trouble shooting steps:

I am also, sn850,just a third of expected and installed to CPU M.2 slot too.
But when I asked the customer service, he said that the speed of read&write is correct, the product is no problem.I dont know why,wtf.