Stability of network cards at 75MHz+

Mark Hahn hahn at
Tue May 16 18:56:56 PDT 2000

On Mon, 15 May 2000, Robert G. Brown wrote:
> A further warning to add to Doug's:  If you have any interest in running
> the BP6 nodes with UDMA enabled, you CANNOT overclock.  I believe that
> Mark Hahn noted that in a comment just yesterday or the day before.  You
> will completely screw up critical timing if you do.

I wouldn't have said that, quite.  the BX chipset, running with FSB=100,
runs PCI at 33, which is the only correct clock (besides 66, which few
PC cards support.)  I would certainly not expect PCI devices to actually
work correctly with non-standard clocks.  some do, some don't, there's no 
way to predict (or validate).  and IDE timing _is_ normally derived 
from the PCI clock.

> I personally run my BP6's at their nice, pedestrian spec speed and they
> are very nice and reliable.

I'm quite happy with my dual celeron 550 BP6.  the HPT controller can deliver
some rather astonishing performance, as well (over 30 MB/s sustained on a
cheap but modern IDE disk!)  the CPU is overclocked (only in a sense,)
but all other components in the system operate at standard clocks.

regards, mark hahn.

More information about the Beowulf mailing list