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buzuddha

Member

Registered: 2020-10-02

Posts: 72

[SOLVED] Hdparm: Low nvme read speed

hdparm -Tt /dev/nvme0n1 yields ~4Gbytes/s

If I boot into windows and run Samsung magician benchmark we approach the 7Gbytes/s theoretical limit (~6.7Gbytes/s). Is there something I need to enable in arch to get my speeds up?

Thanks for any help!

Note:

This is a PCIe 4.0 Samsung 980pro nvme drive. The slot is a MEG Z590I unity PCIe 4.0 m.2 and the CPU is 11th gen Intel, so the ingredients should spell 64Gbits/s (advertised by the motherboard), as we can see it does in the windows example.

Last edited by buzuddha (2021-11-21 14:09:19)

merlock

Member

Registered: 2018-10-30

Posts: 262

Re: [SOLVED] Hdparm: Low nvme read speed

fio might be a better tool to check NVMe drives.

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buzuddha

Member

Registered: 2020-10-02

Posts: 72

Re: [SOLVED] Hdparm: Low nvme read speed

Hmm... I get this:

Writes

sudo fio --name=randwrite --ioengine=libaio --iodepth=1 --rw=randwrite --bs=4k --direct=0 --size=512M --numjobs=2 --runtime=240 --group_reporting
fio: error while loading shared libraries: libtcmalloc.so.4: cannot open shared object file: No such file or directory

Reads

sudo fio --name=randread --ioengine=libaio --iodepth=16 --rw=randread --bs=4k --direct=0 --size=512M --numjobs=4 --runtime=240 --group_reporting
fio: error while loading shared libraries: libtcmalloc.so.4: cannot open shared object file: No such file or directory

A quick googling of this error lands me here

Which says that I need to insall i386 architecture. As this is x86_64 machine I'm wary of insatlling this, but perhaps it's fine to do. Just do'nt know enough about what this might do and don't want to royally alter my system.

Last edited by buzuddha (2021-11-17 13:58:43)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 24,759

Re: [SOLVED] Hdparm: Low nvme read speed

Not really, but it is a bug of the fio package, install gperftools additionally manually: https://bugs.archlinux.org/task/72770

Last edited by V1del (2021-11-17 14:17:35)

buzuddha

Member

Registered: 2020-10-02

Posts: 72

Re: [SOLVED] Hdparm: Low nvme read speed

Thanks for the help y'all!

I ran read tests from Oracles website.

Looks like on a throughput sequential read test you can get above 7GB/s advertised speed, but the range there is 4109MiB/s-6794MiB/s. To be fair, the drive was mounted, but I didn't see anything higher than this running it unmounted from a live CD.

Results are here

Fio reports MiB which is slightly more than 1MB. Random reads are more consistent than sequential.

IOPS Performance Tests
Random Reads: 3600MiB/s +/- 50MiB/s
Sequential Reads: 1455MiB/s-2079MiB/s

Throughput Performance Tests

Random Reads: 4700MiB/s +/- 100MiB/s
Sequential Reads: 4109MiB/s-6794MiB/s

TL;DR - it's pretty good, but I guess I got sold.

Related: If I buy one of these raid nvme pcie 4.0 16x cards and put a striped raid in that sucker, can I into a system on there and get crazy speeds or is that not worth it. Looks like it'd be ~$400 to make a 1TB raid this way.

Last edited by buzuddha (2021-11-21 14:08:55)