Drew,
Thanks for the response. Phil is already intimately familiar with this
but it's an Asus p7t deluxe v2 and the card is a pcie x4 supermicro 8
port AOC-SASLP-MV8.
Simon
On 16 Apr 2011, at 14:45, Drew <drew.kay@xxxxxxxxx
<mailto:drew.kay@xxxxxxxxx>> wrote:
iostat reports 83MB/s for each disk, running up to 830MB/s for all 10
disks,
but the max read speed of the array is approx 256MB/s.
This may be a dumb question but what motherboard & disk controllers
are you using and how are they setup?
That 256MB/s feels to me like you may be bumping up against a
bandwidth limitation of your bus. PCI (32bit/33MHz) is limited to
133MB/s max and PCIe(1.0/2.0) is limited to 250/500MB/s per lane. To
sustain 830MB/s you need at least a PCIe (1.0) x4 or PCI-X 133
controller card which are both rated for (theoretically) 1GB/s.
As an aside, for read speeds on a RAID-5, the parity disk isn't used
so theoretical maximum in this case is 9x83MB/s or 747MB/s. ;-)
--
Drew
"Nothing in life is to be feared. It is only to be understood."
--Marie Curie
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
