Slow ssd speed

[Jack berrey]

I have a B450 aorus M motherboard with an sn750 se 1tb ssd, i am using windows 10. when the pc is just turned on and testing the speed of the ssd it is 3400mb/s but after a while like maybe an hour the speed becomes 800mb/s the temp for both tests are around 40-47c any idea what could be causing this?

[Brooksie359]

Sometimes speeds can slow down when the dram gets completely filled up. Happened with my ssd when doing large file writes granted that is usually when I am writing a big file for awhile. Just to clarify I mean the ram on the ssd not the ram installed on my motherboard. 

[Jack berrey]

6 minutes ago, Brooksie359 said:

Sometimes speeds can slow down when the dram gets completely filled up. Happened with my ssd when doing large file writes granted that is usually when I am writing a big file for awhile. Just to clarify I mean the ram on the ssd not the ram installed on my motherboard. 

i think the sn750 se doesnt have a dram so it cant be that.

[NineEyeRon]

This review does a good job of showing your drive is operating as expected, if not slightly better.

 

https://www.servethehome.com/wd-sn750-se-1tb-nvme-ssd-review-pcie-gen4-ish/3/

[Chris Pratt]

12 minutes ago, Jack berrey said:

i think the sn750 se doesnt have a dram so it cant be that.

Not sure specifically about the SE model, but the SN750 does. However, DRAM would be the best case scenario. If it didn't have DRAM is would have to rely on HMB, which would be exhausted even quicker, or SLC cache, which is far slower.

 

Also, I hope you didn't pay more for the SE, because with your mobo, you don't get any of the benefits over the regular SN750, not that there's much in the first place.

 

 

[Jack berrey]

10 minutes ago, NineEyeRon said:

This review does a good job of showing your drive is operating as expected, if not slightly better.

 

https://www.servethehome.com/wd-sn750-se-1tb-nvme-ssd-review-pcie-gen4-ish/3/

what i understood from this review is that he got the 300mb/s speed with transferring large files. for me the speed on crystaldiskmark becomes 800mb/s with only using the pc to browse and not doing anything demanding, is it normal?

[Jack berrey]

14 minutes ago, Chris Pratt said:

Not sure specifically about the SE model, but the SN750 does. However, DRAM would be the best case scenario. If it didn't have DRAM is would have to rely on HMB, which would be exhausted even quicker, or SLC cache, which is far slower.

 

Also, I hope you didn't pay more for the SE, because with your mobo, you don't get any of the benefits over the regular SN750, not that there's much in the first place.

 

 

Well the SE was cheaper and i thought it was the same as the non SE version but just gen 4 compatible i didn't know it doesn't have a dram  

[Jack berrey]

So from what i have understood this is happening because the slc cache gets filled, but isnt the cache supposed to get flushed after a while or something? the speed stays at 800 mb/s only going to back to the slc cache speed the 3400mb/s after restarting the pc.