Opteron 165 only half utilized???

[Noozer]

Hardware:
- AMD Opteron 165 dual core, 64bit CPU @1.8Ghz stock speeds.
- Mainboard is a DFI Lanparty UT nF4 Ultra-D
- Memory is two pieces of 256meg OCZ PC4200 (DDR 533) DDR in slots 2 and 4.
Automatic configuration in BIOS.
- eVGA nVidia 7600GT PCIe videocard with 256meg of memory
- Seagate 120gig PATA hard drive

Software:
- OS is Windows XP sp2 with MCE 2005.
- Latest nForce 4 chipset drivers installed. AMD CPU drivers are installed.
- Two copies of Prime95 running the Torture Test. Each is set to their own
CPU using the Affinity option of the Advanced menu.

I open the Windows Task Manager and look at the Performance tab. One CPU
shows 100% utilization and the other CPU <5% utilization. WTF?!?!

So I use the Processes tab of Task Manager and set the affinity of each
Prime95 to match what I set in Prime95's Advanced menu. I also set the
Priority to NORMAL for each (Default is Low).

STILL... one core of the Opteron is pegged. The other hardly doing any work
at all.

If I leave it alone and check it later, the utilization MAY have changed to
the other core. I have caught it a few times where both cores are at 100%,
but not often.

Does anyone know WHY Prime95, set at NORMAL priority, and set to use a
specific processor, does NOT use that processor?

 

[JohnS]

STILL... one core of the Opteron is pegged. The other hardly doing any work
at all.

If I leave it alone and check it later, the utilization MAY have changed to
the other core. I have caught it a few times where both cores are at 100%,
but not often.

Does anyone know WHY Prime95, set at NORMAL priority, and set to use a
specific processor, does NOT use that processor?

Are you using the Opteron 32 bit OS drivers or the X2 drivers?
http://www.amd.com/us-en/Processors/TechnicalResources/0,,30_182_871_9033,00.html

Im not even sure they make any difference whatsoever but its something
to check. Theres some WIN XP patches too with some settings people
mention in forums but thats mainly to get glitches out for gaming on
some systems.

I tried it on mine and it worked OK. Seemed to roughly evenly divide
usage , not perfectly but in a rough way. Then When I switched the
affinity settings I did see one CPU fall off and the other rise and
vice versa roughly speaking.

 

[Noozer]

STILL... one core of the Opteron is pegged. The other hardly doing any

Are you using the Opteron 32 bit OS drivers or the X2 drivers?
http://www.amd.com/us-en/Processors/TechnicalResources/0,,30_182_871_9033,00.html

This one:
AMD OpteronT Processor PowerNow! Driver for Windows XP and Windows Server
2003 Version (exe) 1.2.2.

Im not even sure they make any difference whatsoever but its something
to check. Theres some WIN XP patches too with some settings people
mention in forums but thats mainly to get glitches out for gaming on
some systems.

I'm really considering going to 64bit XP as I should have a legit copy in
the next week or so. I still need to check driver availability - I know my
HP 1115 printer is *NOT* supported. (Last HP thing I ever use).

I tried it on mine and it worked OK. Seemed to roughly evenly divide
usage , not perfectly but in a rough way. Then When I switched the
affinity settings I did see one CPU fall off and the other rise and
vice versa roughly speaking.

It just might have been the way Prime95 was running. It was good enough to
test out my overclock.

2.35Ghz on my 165 with memory at 1:1... I should be able to do more, but
that's another thread.