Samsung 970 Evo Plus 1Tb Slow Write Speed

[mikkqu]

I recently switched motherboard from Gigabyte Z390 Designare (setup #1) to Asus ROG Strix Z390-E Gaming (setup #2), same CPU Core i7 9700K.

Once I changed my setup to a new motherboard, I decided to double-check that everything works correctly, and I noticed that my NVME M.2 is running much slower than it used to.

Here is the picture on my setup #1, same say when I bought M.2 SSD, speeds are just as advertised.

Here is a benchmark on my setup #2, as soon as I changed my motherboard to Asus Z390-E:

As it can be seen, Write speeds are much slower.

Both times, SSD is running the latest firmware, same Windows 10 (installed on the same SSD) is running Samsung driver. Bios on Asus ROG motherboard is also latest version. I made sure to update it to a latest version on the setup #2, but that didn't affect the result. I tried both M.2 slots, but with no effect.

The questions are the following:

1. I have used it for a few months, and it filled to about a third of its capacity, as can be seen from screenshot. 380Gb out of 838Gb. Could that be a reason that affected write speed so much / literally crippled it in half? 

2. Another thing that is different between setups, is now I have 8Gb RAM running at 2666Mhz, in setup #1 I had 16Gb RAM running at 3000Mhz. When I run tests, my memory consumption is about 4.5/7.9 GB, so I highly doubt that could affect speed.

3. I noticed that setting "CPU C-states" to disable in Bios, bumps write speed for a few hundreds (or maybe it's just a coincidence, cause the problem still seems to be there). That just made me thing that the bottleneck could be somewhere around CPU:

Both M.2 slots in this motherboard seems to support PCI-E 3.0 x4 and my drive is using it:

Why is it the way it is? Should I blame motherboard? Should I blame SSD? I haven't seen anywhere in Samsung support docs, that the speed supposed to deteriorate with time, or with capacity. I'm super bummed that it used to work fine, and then it just stopped. Could anyone help me troubleshoot this?

 

PS. Also, in device manager, driver prodiver for the disk drive seems to be microsoft (even though it's controlled by Samsung NVMe Controller). Is it okay?

 

Update: From googling this issue, I came up with the tree things to check:

- Set from CPU PCIE Link Mode from AUTO to PCI GEN 3 (unlikely to help, but someone claimed it's actually improve performance. It probably does not).

- windows write cache nvme flag - another person claimed that there is a bug, and if you toggle this flag on and off, the speed gets back to normal

- Update Intel chipset driver

Will check it up tomorrow.

[mikkqu]

Neither of three methods changed things in any way. Have to learn to live with it, I guess.

[Matimba]

I found  the reason  for slow write speed  in my Samsung 1tb Evo plus  to be origin(EA play) software.  When it is running  my write speed dropped from 3300 m/s to 1800 m/s

Just  quit it before  running benchmarks

[Kyouki_IE]

I have been getting 8-900 MB/s write speeds on my 500gb 970 Evo Plus, wasn't sure what was going on.

 

As mentioned on a similar older thread, disabling anti-virus (in my case windows defender) seemed to make the drive run normally again. There are occasions where the drive may produce a lower speed perhaps due to some other interference, but I can say that my main issue was windows defender.