Petr Vandrovec wrote:
Tejun Heo wrote:
Hello,
Petr Vandrovec wrote:
I have recompiled kernel with all debugging disabled, and it brought me
1.5MBps, so it is still consistently 1MBps slower than on sil. Disabling
NCQ seems to improve concurrent access a bit (for which I have no
explanation), while slows down single drive scenario:
With NCQ:
1TB alone: 81.22, 79.86
1TB+1TB: 56.28+56.70, 53.51+56.11
Without NCQ:
1TB alone: 79.78, 80.82
1TB+1TB: 57.99+58.12, 56.50+56.46
3124-2 (norco 4618):
NCQ:
1TB alone: 82.30, 82.43
1TB+1TB: 68.36+68.25
noNCQ:
1TB alone: 82.39, 82.29
1TB+1TB: 70.33+70.32, 69.47+70.01
Unfortunately that enclosure has only two slots used. I'll try to not
forget bring two more disks tomorrow to get it fully populated.
In case you are still follwing this thread, 3124-2 with 4 1TB drives
delivers 58.5MBps for each drive with NCQ enabled, and 60MBps with NCQ
disabled - total 235-240MBps read speed. I would like to see 320MBps,
but apparently today is not my lucky day...
3512 sil, no NCQ:
1TB alone: 82.28, 82.18
1TB+1TB: 47.20+47.54 # Here apparently command based switching or
1.5Gbps link between device and PMP becomes bottleneck
Hmmmm.... Weird. Is the different still there if you take PMP out of
the picture?
Will do tomorrow. I need physical access to the box to do that.
Yes, no difference. 3512 is consistently about 1MBps faster than 3132
when talking to single Hitachi 1TB drive.
Petr
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