Недавно вопросом задавался, хотел узнать сколько из арк может выдать Epyc 7F52 в 8-канальном режиме. Если не использовать сжатие, то результат был следующим и всё упиралось в производительность ЦП:
root@pc:~# fio fio.ini
write: (g=0): rw=read, bs=(R) 1024KiB-1024KiB, (W) 1024KiB-1024KiB, (T) 1024KiB-1024KiB, ioengine=libaio, iodepth=1
...
fio-3.25
Starting 47 processes
Jobs: 47 (f=47): [R(47)][100.0%][r=82.6GiB/s][r=84.6k IOPS][eta 00m:00s]
write: (groupid=0, jobs=47): err= 0: pid=2380076: Mon Dec 11 00:01:52 2023
  read: IOPS=87.3k, BW=85.3GiB/s (91.6GB/s)(853GiB/10003msec)
    slat (usec): min=73, max=48881, avg=534.59, stdev=953.43
    clat (nsec): min=641, max=16384k, avg=1594.93, stdev=36037.08
     lat (usec): min=74, max=48887, avg=536.56, stdev=954.81
    clat percentiles (nsec):
     |  1.00th=[   764],  5.00th=[   844], 10.00th=[   884], 20.00th=[   932],
     | 30.00th=[   980], 40.00th=[  1048], 50.00th=[  1128], 60.00th=[  1240],
     | 70.00th=[  1400], 80.00th=[  1656], 90.00th=[  2192], 95.00th=[  2960],
     | 99.00th=[  5344], 99.50th=[  6688], 99.90th=[ 11712], 99.95th=[ 15040],
     | 99.99th=[136192]
   bw (  MiB/s): min=76800, max=95299, per=4.31%, avg=87646.99, stdev=91.81, samples=893
   iops        : min=76790, max=95287, avg=87642.89, stdev=91.84, samples=893
  lat (nsec)   : 750=0.62%, 1000=31.41%
  lat (usec)   : 2=55.57%, 4=10.09%, 10=2.17%, 20=0.13%, 50=0.01%
  lat (usec)   : 100=0.01%, 250=0.01%, 500=0.01%, 750=0.01%, 1000=0.01%
  lat (msec)   : 2=0.01%, 4=0.01%, 10=0.01%, 20=0.01%
  cpu          : usr=0.52%, sys=59.95%, ctx=257025, majf=0, minf=39045
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=873364,0,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=1
Run status group 0 (all jobs):
   READ: bw=85.3GiB/s (91.6GB/s), 85.3GiB/s-85.3GiB/s (91.6GB/s-91.6GB/s), io=853GiB (916GB), run=10003-10003msec
Немного улучшил результат))
root@pc:~# fio fio.ini
read: (g=0): rw=read, bs=(R) 1024KiB-1024KiB, (W) 1024KiB-1024KiB, (T) 1024KiB-1024KiB, ioengine=libaio, iodepth=1
...
fio-3.33
Starting 47 processes
Jobs: 47 (f=47): [R(47)][100.0%][r=114GiB/s][r=117k IOPS][eta 00m:00s]
read: (groupid=0, jobs=47): err= 0: pid=697790: Sun Oct 27 18:18:21 2024
read: IOPS=118k, BW=115GiB/s (123GB/s)(1150GiB/10003msec)
slat (usec): min=73, max=18246, avg=396.84, stdev=132.93
clat (nsec): min=701, max=872763, avg=1239.62, stdev=2386.86
lat (usec): min=74, max=18250, avg=398.08, stdev=133.20
clat percentiles (nsec):
| 1.00th=[ 804], 5.00th=[ 900], 10.00th=[ 940], 20.00th=[ 980],
| 30.00th=[ 1012], 40.00th=[ 1048], 50.00th=[ 1096], 60.00th=[ 1128],
| 70.00th=[ 1176], 80.00th=[ 1240], 90.00th=[ 1416], 95.00th=[ 1848],
| 99.00th=[ 4576], 99.50th=[ 5344], 99.90th=[ 6752], 99.95th=[11072],
| 99.99th=[55040]
bw ( MiB/s): min=116280, max=120621, per=100.00%, avg=117818.08, stdev=22.16, samples=893
iops : min=116278, max=120618, avg=117817.89, stdev=22.15, samples=893
lat (nsec) : 750=0.04%, 1000=23.78%
lat (usec) : 2=71.94%, 4=2.79%, 10=1.40%, 20=0.03%, 50=0.01%
lat (usec) : 100=0.01%, 250=0.01%, 500=0.01%, 750=0.01%, 1000=0.01%
cpu : usr=0.58%, sys=50.43%, ctx=1017304, majf=0, minf=12514
IO depths : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
issued rwts: total=1177162,0,0,0 short=0,0,0,0 dropped=0,0,0,0
latency : target=0, window=0, percentile=100.00%, depth=1
Run status group 0 (all jobs):
READ: bw=115GiB/s (123GB/s), 115GiB/s-115GiB/s (123GB/s-123GB/s), io=1150GiB (1234GB), run=10003-10003msec