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

[Mathieu Chouquet-Stringer <mchouque@e-steel.com>]

timw@splhi.com (Tim Wright) writes:

> 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.

Sadly, I am sure that your "well-designed" system must be costly as
hell... :(

-- 
Mathieu CHOUQUET-STRINGER              E-Mail : mchouque@e-steel.com
     Learning French is trivial: the word for horse is cheval, and
               everything else follows in the same way.
                        -- Alan J. Perlis
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