Intel 860 PCI bandwidth problem

Steffen Persvold sp at scali.com
Sat Jan 19 08:47:47 EST 2002


Greg Lindahl wrote:
> 
> On Fri, Jan 18, 2002 at 10:40:37PM -0700, Maurice Hilarius wrote:
> 
> > Implication: The early termination limits the maximum bandwidth to ~90 MB/s.
> 
> That note sounds like it's not talking about DMA operation. You did
> look at the Myrinet Experiences website
> 

I think you misunderstood, "memory read multiple" is the PCI instruction used by most DMA engines
(SCSI, ethernet, SCI and I would guess Myrinet) when they read from RAM (source machine). On the
other side (destination), "memory write invalidate" is normally used.

However, this errateadoesn't limit the SCI DMA bandwith to ~90MB/s either, 210MB/s is the most I've
seen so far.

Regards,
-- 
  Steffen Persvold   | Scalable Linux Systems |   Try out the world's best   
 mailto:sp at scali.no  |  http://www.scali.com  | performing MPI implementation:
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