Re: [myrinet] RE: PCI bus speed

On Wed, Aug 29, 2001 at 03:40:01PM -0400, Tenhave, Tim wrote:
> Hi Keith,
> 
> The AlphaServer 4100 and all it flavors (4000, 4100, 4100LP) only offers
> 33MHz PCI.  All Alpha based products to date (August 2001) have either been
> 32bit/33MHz or 64bit/33MHz or a combination of those two.
> 
> Compaq will not be shipping an Alpha processor based 64bit/66MHz PCI bus
> system until later this year.
> 
> I cannot comment on Alpha clones.
> 

So, we should comment that at this moment alpha-based beowulf clusters
are inherently worse as intel/sparc based, for throughput.
This is not true I think for high-end servers (but they are not used
as beowful PU :) generally). 
But for clones of course.

> tim
> 
> > Tim Tenhave
> > Compaq Computer Corp.
> > HPS/HPTC Custom Engineering
> > ZKO1-1/D41
> > 110 Spit Brook Road
> > Nashua, NH 03062
> > * (603) 884-4272 
> > *Email:  [email protected]
> > FAX (603) 884-3313
> > http://www.compaq.com/solutions/customsystems/hps/linux.html
> > 
> 
> 
> -----Original Message-----
> From: Keith Parkins [mailto:[email protected]]
> Sent: Wednesday, August 29, 2001 1:09 PM
> To: [email protected]
> Subject: [myrinet] PCI bus speed
> 
> 
> Hi,
> 
> We have an alpha (4100) and were only getting 33Mhz set for the PCI bus
> rate when we loaded the gm driver. I noticed that the myri(LANai7) cards
> support 66Mhz bus rates but only if the PCI bus is 3.3v. I have been
> digging around and can't find whether or not the bus on the 4100 is 3.3v
> or 5v. It is a rev3 PCI bus. Does anyone know this spec? If this is not
> why the bus is getting set to 33Mhz, how do I set it to 66 Mhz? I didn't
> notice anything obvious in sysconfigtab (running Tru64 v.4.0F).
> 
> Thanks!
> Keith

-- 
Francesco P. Lovergine