David said:
The computer is idle during the spikes. I try not to do anything
(besides the processes running in the background like virus checker).
I ran AMD clock, which tells me that both cores are running at
2000-2025.
I don't really understand the PRIME95 stuff - do I run it in the
background? It tells me it will take an hour to test?!? What are the
steps, Paul, if you don't mind? I am running XP. I think the
affinity program is associated with that, right?
There is a picture here, of setting affinity in what I presume is
WinXP. I have Win2K SP4 here, and my Task Manager is not the same
as this. What you would want to do, is start SuperPI, then open
Task Manager, set affinity to CPU0 or to CPU1, but not both.
Then compare whether both cores execute the benchmark in the same time.
http://www.xtremesystems.org/forums/showthread.php?t=142439
There are separate programs as well, for setting the affinity
without the Task Manager. There is a download here, for example,
that claims to allow you to manage affinity (sticking the program
so it only runs on one core, and doesn't migrate back and forth
between cores, multiple times per second).
http://www.tomshardware.com/2004/05/28/getting_more_bang_out_of_your_dual_processing_buck/index.html
Prime95, for me at least, is for testing integrity. I use the
Torture Test, and as long as it doesn't report errors, then
I know my RAM and CPU are working correctly. If Prime95 stops
with an error, say a rounding error, that could mean it
encountered a memory error. Or it could mean the processor
itself made an error. An error in Prime95 means something is
not optimally adjusted in your system, or it could mean the
memory is bad. It could even be flagging a bad processor. It
all depends on what instruction types that Prime95 uses, as to
how complete a test coverage you get. If it didn't use any SSE
instructions for example, then you wouldn't know if there were
any problems with SSE, and you might only see those with a
transcoding or compression application.
I notice Prime95 does have an affinity setting now, so you
could test one core at a time if you wanted.
While Prime95 does have a benchmarking facility, I don't know
if there are enough benchmarks around, to allow comparing to
other 3800+ X2 owners. At the moment, we are dealing with
a performance problem, and integrity testing is an entirely
different issue. It is possible to "compute correctly", but
at a reduced speed. And what we're searching for right now,
is what could be the source of a speed problem. If you managed
to get a benchmark to run at full speed, either the speed
changes with the core you are running on, or the recent driver
update you did, has changed things.
Paul