Robin H. Johnson wrote:
On Wed, Sep 05, 2007 at 05:08:00AM -0700, Petr Vandrovec wrote:
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...
Just to confirm, how were you testing the multiple drive combination?
Concurrent hdparm -t, like
hdparm -t /dev/sdd & hdparm -t /dev/sde & hdparm -t /dev/sdf & hdparm -t
/dev/sdg & sleep 20
(and from hdparm output & visually confirmed that all activity LEDs go
on & off simultaneously)
So NCQ should not be able to show any (definitely not huge) benefits,
but there should not be any reason to not get 4x 1 drive speed as long
as neither PMP link nor PCI-X limits are hit.
Petr
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