Follow up on dual CPU weirdness - time issues

Daniel McNamara daniel at
Mon May 20 20:01:26 EST 2002

Hey guys,

Some time ago some of you may remember I sent an email to this list 
regarding a weird situation with a dual CPU machine I have where the 
system clock would run at double speed if I had an SMP kernel running 
(didn't matter if it was the stock Red Hat SMP kernel or one compiled 
from scratch) yet at normal speed if a I had a single CPU kernel running.

After sometime of ignoring this machine whilst I got on with other 
problems I've come back to it. A thought occured to me it might be a 
hardware issue so I threw myself on Google and did a bit more looking. 
What I found was a set of jumper settings to do with CPU core and bus 
frequencies. The table which I refer to is found at:

In the table labelled "JP1 settings". Having examined the CPU board it 
would appear this board is currently set to 4/1

However I must confess I have no idea what I'm looking at here in this 
table. I brought this machine second hand and I have no idea if it was 
in a different configuration prior to my purchase of it. It currently 
has in it two PII 233MHz chips. Could anyone out there give me an idea 
if I'm going along the right track here? Should the jumpers be on a 
different settting? Or should not fiddle with them lest I nuke the CPU's?

Anyone who could give me an idea of if this table is even relevant to 
this situation would be helpful.



More information about the linux mailing list