Re: Call for testers with NVMe

From: Christos Longros <chris.longros_at_gmail.com>
Date: Tue, 08 Sep 2026 13:14:08 UTC
Seen no difference. I used two Gen4 drives, Samsung 990 PRO and Crucial
T500:

old = D59151-52, new = +D59153-54, arb = +D59155

990 PRO (RAB 2)         old    new    arb
perftest 4k x4   IO/s   694k   688k   694k
perftest 128k x1 MB/s   5547   5557   5563
fio 4k QD32      IOPS   651k   626k   625k
fio 4k QD1 psync IOPS  29.5k  29.1k  29.2k
fio seq 1m QD8   MiB/s  4960   4954   5020

T500 (RAB 6)            old    new    arb
perftest 4k x4   IO/s   468k   472k   474k
perftest 128k x1 MB/s   4861   4873   4876
fio 4k QD32      IOPS   339k   340k   339k
fio 4k QD1 psync IOPS  14.9k  14.9k  14.9k
fio seq 512k QD8 MiB/s  2661   2665   2666

Raw logs available on request.

On Tue, Sep 08, 2026 07:03 AM, Warner Losh <imp@bsdimp.com> wrote:

> So we have a variety of NVMe drives with non-zero ARB values, but we're
> still seeing line rate or datasheet maximums on our streaming workload...
>
> What workload would show an improvement?
>
> I'd really prefer to get a chance to test these on Netflix workloads
> before you land it (if it's not too late).
>
> Warner
>
> On Thu, Sep 3, 2026 at 7:07 AM Abdelkader Boudih <seuros@freebsd.org>
> wrote:
>
>> Thanks for testing.
>>
>> This shows a 47% improvement , 780 MB/s to 1150 MB/s in sequencial output
>> and slight increase in the random seek.
>>
>> Linux numbers are useful but that was tested against another filesystem.
>>
>> Also, your 2 kernels are from July 12 and Sep 3 ,  So that proof that
>> when people will upgrade from 15.x , they will get an increase that was not
>> only tested in 1 tester.
>>
>> I will wait for Olivier's response before we land these.  (I already have
>> more changes that i'm trying to benchmark here).
>>
>> Best,
>> Abdelkader
>>
>> On Thu, 3 Sep 2026, at 12:12, Martin Cracauer wrote:
>>
>> Abdelkader Boudih wrote on Wed, Sep 02, 2026 at 10:41:25AM +0100:
>> > Hi all,
>> >
>> > I am about to land the D59156 stack in about 24 hours:
>> https://reviews.freebsd.org/D59156
>> >
>> > It is a stack of 6 commits, D59151 --> D59156.
>> >
>> > This stack allows NVMe drives to run at full speed and use all
>> available lanes, instead of being quirked to use only one.
>>
>> Here are my benchmarks.  Machines are Thinkpad T14 AMD gen 1 with 48
>> GB RAM and 1 TB NVMe WD black sn850x.
>>
>> sn850x 1TB on -current ufs: main-n287387-7aa34e12c9e1 Jul 12, 2026`
>>          ---Sequential Output----- ---Input---- ------Random--
>> -----Random----
>>          ---Block---- ---Rewrite-- ---Block---- ---ro Seeks--- -Seeks
>> rewrite-
>>     MB    M/sec %CPU    M/sec %CPU   M/sec %CPU      /sec  %CPU     /sec
>> %CPU
>> 65536   780.7  33.8   779.4  38.2   2301.4  53.6  73650.7  32.1 30248.5
>> 25.3
>> cseekbench: 126.585791 usec/access 0.030 GB/sec
>> main-n288812-799061fc769c Sep 3:
>>     MB    M/sec %CPU    M/sec %CPU   M/sec %CPU      /sec  %CPU     /sec
>> %CPU
>> 65536  1150.6  49.2   776.9  40.5   2229.2  60.5  86489.4  37.8 33537.9
>> 28.0
>> cseekbench: 127.185498 usec/access 0.030 GB/sec
>>
>> Linux 6.17.0-rc2 ext4fs:
>>          ---Sequential Output----- ---Input---- ------Random--
>> -----Random----
>>          ---Block---- ---Rewrite-- ---Block---- ---ro Seeks--- -Seeks
>> rewrite-
>>     MB    M/sec %CPU    M/sec %CPU   M/sec %CPU      /sec  %CPU     /sec
>> %CPU
>> 65536  2693.9  95.4   714.3  37.7   2786.7  63.0  44818.0  30.1 26286.2
>> 23.5
>>     MB    M/sec %CPU    M/sec %CPU   M/sec %CPU      /sec  %CPU     /sec
>> %CPU
>> 65536  1630.2  96.7   628.4  56.6   2520.4  71.7  41362.8  49.8 24476.6
>> 36.8
>> cseekbench: 87.998063 usec/access 0.043 GB/sec
>> Linux grisu 6.8.0-137-generic:
>>     MB    M/sec %CPU    M/sec %CPU   M/sec %CPU      /sec  %CPU     /sec
>> %CPU
>> 65536  1133.0 100.4   742.4  80.7   1831.7  99.0  39877.3  46.4 24268.6
>> 40.4
>> cseekbench: 118.671478 usec/access 0.032 GB/sec
>> Linux grisu 7.2.3:
>>     MB    M/sec %CPU    M/sec %CPU   M/sec %CPU      /sec  %CPU     /sec
>> %CPU
>> 65536  1562.6  97.5   617.6  57.9   2466.8  74.2  41675.5  50.3 23832.1
>> 39.2
>> cseekbench: 87.090687 usec/access 0.044 GB/sec
>>
>>
>> Benchmarks are here:
>> https://github.com/cracauer/bench-disk-bonnie (pre-GPL fork of bonnie)
>> https://github.com/cracauer/cseekbench
>>
>> Martin
>> --
>> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>> Martin Cracauer <cracauer@cons.org>   http://www.cons.org/cracauer/
>>
>>
>>