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Nvme write speed dropped dramatically

dinit

Used to have (kdiskmark) ~2500 write speed
Now it's dropped to ~6 Mb/s
io scheduler change to [none] didn't help.

tried linux-zen kernel with no joy as well

Code: [Select]
dd if=/dev/zero of=tempfile bs=1M count=512 conv=fdatasync,notrunc status=progress oflag=direct
536870912 bytes (537 MB, 512 MiB) copied, 79 s, 6,8 MB/s

Re: Nvme write speed dropped dramatically

Reply #1 –
Do you run a trim regularly?

artist

Re: Nvme write speed dropped dramatically

Reply #3 –
LiveUSB boot (mxlinux)
gnome-disk-utility shows normal write speed


Re: Nvme write speed dropped dramatically

Reply #4 –
That rules out hardware :-)  It's time to compare linux driver types and versions.

artist

Re: Nvme write speed dropped dramatically

Reply #5 –
Total reinstall with new partitioning order and openRC init  :'(
Speeds are back to normal. But now I think nvme hardware issue could be the case. At least partly.
Code: [Select]
KDiskMark (3.2.0): https://github.com/JonMagon/KDiskMark
                    Flexible I/O Tester (fio-3.39): https://github.com/axboe/fio
--------------------------------------------------------------------------------
* MB/s = 1,000,000 bytes/s [SATA/600 = 600,000,000 bytes/s]
* KB = 1000 bytes, KiB = 1024 bytes

[Read]
Sequential   1 MiB (Q=  8, T= 1):  3542.486 MB/s [   3459.5 IOPS] <  2276.08 us>
Sequential 128 KiB (Q= 32, T= 1):  3554.494 MB/s [  27769.5 IOPS] <  1141.27 us>
    Random   4 KiB (Q= 32, T=16):  1061.505 MB/s [ 265377.1 IOPS] <   480.17 us>
    Random   4 KiB (Q=  1, T= 1):    61.069 MB/s [  15267.3 IOPS] <    62.43 us>

[Write]
Sequential   1 MiB (Q=  8, T= 1):  2561.757 MB/s [   2501.7 IOPS] <  3060.12 us>
Sequential 128 KiB (Q= 32, T= 1):  2574.172 MB/s [  20110.7 IOPS] <  1562.99 us>
    Random   4 KiB (Q= 32, T=16):   625.989 MB/s [ 156498.3 IOPS] <   815.30 us>
    Random   4 KiB (Q=  1, T= 1):   238.829 MB/s [  59707.4 IOPS] <    13.44 us>

Profile: Default
   Test: 1 GiB (x3) [Measure: 5 sec / Interval: 5 sec]
   Date: 2025-07-01 14:54:07
     OS: artix unknown [linux 6.15.2-artix1-1]
 Target: /home 0% (0,00/1,75 TiB) [Vi3000 Internal PCIe NVMe M.2 SSD 2TB]

Re: Nvme write speed dropped dramatically

Reply #6 –
NVME drives can throttle due to increased temperature which can occur during heavy use, heatsinks are optional but will increase performance in those situations.

Re: Nvme write speed dropped dramatically

Reply #7 –
Quote
NVME drives can throttle due to increased temperature
true. But not in my case. Never had over 59 grad C even w/o heatsink. Neither heavy usage.

Observations showed that reading speed never dropped unlike writing with dramatic diff. Still think of some hardware issues. Pretty cheap nmve (kioxia inside). And thus need for more testing.