[ILUG] Highpoint Sata RAID

[Paul Jakma]

On Tue, 22 Mar 2005, Niall O Broin wrote:

> software runs on a processor on the controller. With Linux software RAID, or 
> RAID on the cheap Highpoint or Promise cards, the software runs on the host 
> CPU.

Interestingly, the Promise SX4 SATA cards actually /are/ hardware 
RAID. At least, they have onboard RAM and a XOR engine to be able to 
accellerate RAID-5. The RAM allows the OS to only have to copy data 
across the PCI bus once, and then issueing the disk transaction from 
the card-local data.

Sort of a hardware-accellerated card. It doesn't get involved in the 
details of managing RAID-5 - left for OS - but does provide the 
hardware needed for fast RAID.

Linux md doesnt make use of that onboard hardware yet though.

regards,
-- 
Paul Jakma	paul at clubi.ie	paul at jakma.org	Key ID: 64A2FF6A
Fortune:
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