Slow write speeds Samsung PM951

[Fabtab]

Having slow write speed problems with my Samsung PM951 MVMe PCIe 3 Drive on an X360 Spectre X5X71EA.

Any thoughts appreciated for trying settings that I may have messed up etc.

 

 

[porina]

Quote

With this testing I found a "problem" I didn't know I had on one system... it has a Samsung PM951 256GB NVMe drive. I picked it as a balance between cost, capacity and giving a bit more performance than SATA drives. It runs my VR system and I've not had any problems with it, until I ran AS SSD. All was fine apart from the 4k random write. It was stupidly slow estimating 1 MB/s and around 20 minutes to run. I aborted that, finished the other tests (write latency was 4ms!!!) and hit Google to try and work out what was up. Found a comment saying that disabling the Windows write cache flush resolves it, and sure enough, doing that made write speeds go up a lot, and latency right down. The only caution here is Windows says that there is a risk of data loss in the event of power loss if I use that setting. What was reporting 1 MB/s in AS SSD is now 150MB/s. I didn't do a CDM before the setting change, but writes there are in 300MB/s ball park apart from 4k which is 200MB/s.

My notes from when I encountered the same problem.

[Mr.Meerkat]

8MB/s writes...AHAHAHAHAHAHAHAHAHAHAHAH

[Fabtab]

Thanks I'll try that

[Fabtab]

Yup, that seems to work as expected.

Thanks for the that, I'll keep in mind the data loss!