NVME Disks - not maximum speed - very slow

[wolfyrion]

Hi ,

I have recently purchased 2x NVME Disks

Local Storage: total: 20.94 TiB used: 4.74 TiB (22.6%)
ID-1: /dev/nvme0n1 vendor: Samsung model: SSD 970 PRO 1TB size: 953.87 GiB
ID-2: /dev/nvme1n1 vendor: Western Digital model: WDS200T1X0E-00AFY0 size: 1.82 TiB

Supposedly the WD_BLACK™ SN850 NVMe™ SSD

Sequential Read Performance 7000MB/s
Sequential Write Performance 5100MB/s

and The Samsung 970 Pro

3,500MB/s Seq. Read
2,700MB/s Seq. Write

But this is what I am getting

/dev/nvme1n1:
Timing O_DIRECT cached reads: 5660 MB in 2.00 seconds = 2831.33 MB/sec
Timing O_DIRECT disk reads: 7538 MB in 3.00 seconds = 2512.64 MB/sec
[wpc wolfyrion]# hdparm -Tt --direct /dev/nvme0n1

/dev/nvme0n1:
Timing O_DIRECT cached reads: 6068 MB in 2.00 seconds = 3035.03 MB/sec
Timing O_DIRECT disk reads: 8926 MB in 3.00 seconds = 2975.30 MB/sec

Samsung seems to be ok but the WD is like 1/3 of its performance ><

[leledumbo]

That WD drive is a PCIe 4.0 one, if you install it on a PCIe 3.0 slot, of course it’s gonna be limited by that (which I can guess from the given speed).

[wolfyrion]