Subject: Re: pciide performance on alpha
To: Ken Wellsch <kwellsch@link.link-systems.com>
From: Jason Thorpe <thorpej@nas.nasa.gov>
List: port-alpha
Date: 08/12/1999 09:59:31
On Thu, 12 Aug 1999 09:30:53 -0400 (EDT) 
 Ken Wellsch <kwellsch@link.link-systems.com> wrote:

 > I believe Andreas mentioned working with a PC164SX?  I too have an SX.
 > I guess I should have sprung for the extra $$'s and got an LX like all
 > the other alpha folks in-the-know as I too have noted the anemic EIDE
 > performance vs the same drive and OS on an i386 platform (both using plain
 > DMA).  When I moved my IBM drive from my PPro box to my SX box, I "lost"
 > at least 50% and I'd claim 75% on transfer rates, based on bonnie
 > measurements at that time.

Note that the 164SX has a wimpy memory bus speed compared to the 164LX
and the original PC164 (which had the best of all of them, actually).  This
might contribute.

If you get better transfer rates on the *same machine* under a different
OS (as was implied earlier in the thread, I think), then there may be
a problem with how we initialize the Cypress controller... but that
would be the only issue; the vast majority of the PCI IDE code is
shared between all controller types.

        -- Jason R. Thorpe <thorpej@nas.nasa.gov>