Re: RAID 5 performance issue.

[Andrew Clayton <andrew@digital-domain.net>]

On Wed, 03 Oct 2007 19:53:08 +0200, Goswin von Brederlow wrote:

> Andrew Clayton <andrew@pccl.info> writes:
> 
> > Hi,
> >
> > Hardware:
> >
> > Dual Opteron 2GHz cpus. 2GB RAM. 4 x 250GB SATA hard drives. 1
> > (root file system) is connected to the onboard Silicon Image 3114
> > controller. The other 3 (/home) are in a software RAID 5 connected
> > to a PCI Silicon Image 3124 card. I moved the 3 raid disks off the
> > on board controller onto the card the other day to see if that
> > would help, it didn't.
> 
> I would think the onboard controller is connected to the north or
> south bridge and possibly hooked directly into the hyper
> transport. The extra controler is PCI so you are limited to
> theoretical 128MiB/s. For me the onboard chips do much better (though
> at higher cpu cost) than pci cards.

Yeah, I was wondering about that. It certainly hasn't improved things,
it's unclear if it's made things any worse..

> MfG
>         Goswin


Cheers,

Andrew