Re: Abysmal RAID 0 performance on 2.4.0-test10 for IDE?

From: Tim Wright (
Date: Thu Dec 28 2000 - 16:42:44 EST

On Wed, Dec 27, 2000 at 04:23:43PM +0000, Paul Jakma wrote:
> On Tue, 26 Dec 2000, Ian Stirling wrote:
> > The PCI bus can move around 130MB/sec,
> in bursts yes, but sustained data bandwidth of PCI is a lot lower,
> maybe 30 to 50MB/s. And you won't get sustained RAID performance >
> sustained PCI performance.

No. A well-designed card and driver doing cache-line sized transfers can
achieve ~100MB/s. On the IBM (Sequent) NUMA machines, we achieved in excess
of 3GB/s sustained read I/O (database full table scan) on a 16-quad (32 PCI
bus) system. That works out at around 100MB/s per bus.



Tim Wright - or or
IBM Linux Technology Center, Beaverton, Oregon
"Nobody ever said I was charming, they said "Rimmer, you're a git!"" RD VI
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