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Slow NVMe performance on DIMM2 slot. Slower than laptop.

Level 7
Crystal Bench with 601 BIOS


Crystal Bench from my Laptop with NVMe drive


I have reset the bios and cleared all overclock settings.

This is causing the system to run slower than my laptop. Loading up photoshop feels like I have a sata platter drive.

Random 4k Q32T1 benchmark is the problem.
IOPS are showing about 24k to 30k should be benching 200k iops minimum.

I can't use the main DIMM slot on the motherboard to test it right now because I have hardtubing for watercooling and can't remove my graphics card without draining the whole system and undoing the fittings which would take a while.

Can anybody confirm if they are getting better results with crystal mark?

CrystalDiskMark 5.2.2 x64 (C) 2007-2017 hiyohiyo
Crystal Dew World :
* MB/s = 1,000,000 bytes/s [SATA/600 = 600,000,000 bytes/s]
* KB = 1000 bytes, KiB = 1024 bytes

Sequential Read (Q= 32,T= 1) : 3267.551 MB/s
Sequential Write (Q= 32,T= 1) : 2131.028 MB/s
Random Read 4KiB (Q= 32,T= 1) : 126.813 MB/s [ 30960.2 IOPS]
Random Write 4KiB (Q= 32,T= 1) : 102.182 MB/s [ 24946.8 IOPS]
Sequential Read (T= 1) : 2146.020 MB/s
Sequential Write (T= 1) : 2031.733 MB/s
Random Read 4KiB (Q= 1,T= 1) : 37.151 MB/s [ 9070.1 IOPS]
Random Write 4KiB (Q= 1,T= 1) : 78.816 MB/s [ 19242.2 IOPS]

Test : 1024 MiB [C: 18.9% (180.4/953.3 GiB)] (x5) [Interval=5 sec]
Date : 2017/09/19 21:16:19
OS : Windows 10 Professional [10.0 Build 15063] (x64)

dejanh wrote:
I'm going to necro this thread because I have been struggling and ignoring NVMe random 4k read and write issues for years, and have finally had it. I have two Samsung 980 Pros 512GB each and a single 970 Pro Plus 2TB drive and I am getting ridiculously low random 4k R/W at QD32. Like when I say ridiculous, I mean I get 90% lower performance than spec. My 2TB 970 Evo Plus running connected to the motherboard slot directly (not the DIMM.2 card) gets 360k IOPS random read, and only 20k IOPS random write. Even my ROG X13 Flow laptop smokes this using the no-name drive it comes with. The write IOPS on the laptop are literally 5x better.

It does not matter if the drive is OS drive or storage drive, and it does not matter whether Samsung NVMe driver is installed or not. The performance is essentially the same abysmal performance. I am so fed up with this that I am about to make a trip to the store to buy a new Ryzen machine instead of the Threadripper 2950x setup I currently have just to prove the point that something is really messed up with this chipset and NVMe. Has anyone been able to figure this out? Note I am now running Windows 11, I used to run Windows 10, and it doesn't matter whether it is a fresh install or not. Performance is abysmal either way. The 2950x is running on a Zenith Extreme Alpha board, running the latest UEFI/BIOS.

I had the same issue as you on a Intel X299 Rampave VI Extreme Motherboard with DIMM.2. Move your NVME drives to the normal NVME ports located near the PCIE slots. DIMM.2 as a technology is a failure. RAM slots are meant for volatile memory only. Asus needs to find a better way to add more M.2 slots without routing through the memory subsystem. It was taking me 5 minutes to unzip 5MB zip files. Finally I had enough and removed DIMM.2 from the equation. It was like I bought a brand new PC with top-of the line components after I made the change.