Michael Tokarev wrote:
[]
> I'm planning to test several models of SCSI drives. On SCSI front
> (or maybe with different drives - I don't know) things are WAY more
> interesting wrt TCQ. Difference in results between 1 and 32 threads
> goes up to 4 times sometimes!. But I'm a bit stuck with SCSI tests
> since I don't know how to turn off TCQ without rebooting a machine.
A quick followup, to demonstrate the "interesting" part.
Seagate SCSI ST3146854LC drive, 140Gb, 15KRPM, write cache disabled,
queue depth = 32:
BlkSz Trd linRd rndRd linWr rndWr rndR/W
4k 1 37.9 0.6 0.9 0.6 0.4/ 0.3
4 0.9 0.7 0.6/ 0.4
32 1.5 1.1 0.9/ 0.4
8k 1 75.2 1.2 1.9 1.1 0.8/ 0.6
4 1.7 1.5 1.1/ 0.7
32 2.9 2.2 1.7/ 0.9
16k 1 82.3 2.4 3.6 2.3 1.5/ 1.2
4 3.3 2.9 2.2/ 1.4
32 5.5 4.3 3.3/ 1.7
32k 1 86.3 4.7 6.9 4.4 2.9/ 2.3
4 6.4 5.6 4.2/ 2.7
32 10.2 8.0 6.2/ 3.1
128k 1 86.5 15.8 26.6 14.9 9.5/ 7.7
4 20.6 18.2 13.5/ 8.5
32 29.2 24.8 18.3/ 9.1
1024k 1 88.6 46.7 63.1 48.2 25.3/25.3
4 51.7 51.3 33.5/21.8
32 55.9 57.3 37.6/19.0
Fujitsu SCSI MAX3147NC drive, same parameters:
BlkSz Trd linRd rndRd linWr rndWr rndR/W
4k 1 37.4 0.7 1.0 0.6 0.4/ 0.3
4 0.9 0.8 0.6/ 0.4
32 1.5 1.2 0.9/ 0.4
8k 1 32.9 1.3 1.9 1.2 0.7/ 0.7
4 1.8 1.5 1.2/ 0.7
32 2.8 2.3 1.7/ 0.9
16k 1 89.6 2.6 3.7 2.4 1.4/ 1.3
4 3.5 3.0 2.4/ 1.4
32 5.4 4.4 3.3/ 1.7
32k 1 87.9 4.8 7.0 4.4 2.6/ 2.6
4 6.8 5.6 4.6/ 2.7
32 9.9 8.3 6.2/ 3.1
128k 1 90.7 16.2 22.5 15.3 8.6/ 8.6
4 21.8 18.6 15.0/ 8.1
32 28.6 25.0 18.2/ 9.1
1024k 1 90.6 48.9 60.0 47.4 25.3/25.9
4 55.6 51.7 34.4/22.5
32 59.8 56.2 38.6/19.7
/mjt
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