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Neo.cmg · Oct 21, 2007, 05:50 PM

I recently opened Core Duo Temp on my dual 2.66Ghz Core Duo Mac Pro. I was surprised to see that it was showing my minimum CPU frequency as 1.0Ghz and my maximum at 1.33Ghz. The current value was at the max frequency. This was even what was recorded when my SMP Folding @ Home client was reportedly taking 100% of my CPU cycles, and Activity Monitor confirmed all 4 cores were being pushed to their limits.

Now I fear that there is either something wrong with my computer's CPU, or there is something wrong with the Core Duo Temp application. Only, I don't know of a way to get an Apple sanctioned application to report what my computer's CPU frequency actually is, so that if there is a problem I can go to Apple and say I have a hardware problem and have them agree...

Alternately, I'm not quite certain why I put so much weight into what this third-party app, Core Duo Temp is reporting, but it seems to be reporting accurately for others.

So, is there anything I can try to help further diagnose this issue? I have tried calling Apple already, but the issue wasn't one they were familiar with and weren't much help over the phone... Any help would be greatly appreciated.

Thanks.

mduell · 06:55 PM

Try sysctl hw.cpufrequency in Terminal.

And before the pedants get to you, your Mac Pro has Xeons, not Core Duos.

Neo.cmg · Oct 21, 2007, 07:16 PM

Thanks. The sysctl shows the cpu frequency as:

hw.cpufrequency: 2660000000

Now, is this command just getting it's information the same place as say the About This Mac and the Apple System Profiler, or does it display an actual time dependent value?

Is the reason why CoreDuoTemp show the max cpu frequency as 1.33Ghz related to the fact that the CPUs in the Mac Pro aren't actually Intel Core Duos?

mduell · Oct 21, 2007, 08:09 PM

It could just be a CoreDuoTemp bug... try one of the other similar apps.

I don't suppose you have Windows installed? cpu-z would tell you.

oliviergaston · Nov 6, 2007, 12:34 PM

CoreDuo Temp may be running in 32bit only and thus reading half the speed of the 64bit Xeon that you have.

this statement doesn't make a lot of sense, really but 1.33 really is half of 2.66.

it's a shot in the dark. who knows...

mduell · Nov 6, 2007, 06:50 PM

Originally Posted by oliviergaston

CoreDuo Temp may be running in 32bit only and thus reading half the speed of the 64bit Xeon that you have.

No. Bits have nothing to do with frequency.

Waragainstsleep · Nov 7, 2007, 05:56 PM

CPU speed is usually a factor of bus speed which is 1.33GHz in a Mac Pro. Maybe thats what its measuring? Can't think why. I know the 8 cores had a known issue mis-reporting their speeds

ChrisB · Nov 7, 2007, 11:43 PM

This sounds like a software bug. Have they released an updated version?

P · Nov 8, 2007, 08:44 AM

Have you tried rebooting into Windows or some Linux variant to see what they report?

zeropoint · Dec 8, 2007, 12:15 PM

I am having similar problems on a MBP 2.4. I use it for audio running a program called Ableton Live. Recently I noticed a drop off in performance. I ran the user community's performance test and was getting cpu meter levels almost exactly double those of users on the same machine running the same os. I have now crosschecked with Xbench and my cpu test results in half the total of other users on the same machine. (with Xbench the higher the number the better the performance) I tried Core Duo Temp. My system shows a max clock speed of 2.0 with current at 1.33Ghz. This speed does not change regardless of the load. Something is definitely up with my processor.........

chris v · Dec 9, 2007, 10:38 AM

Do the Mac Pros still have the system preference in Energy Saver>Options where you've got the pop-up menu for "Reduced, Automatic, and Highest?" or is that just a PPC thing?

"Automatic," the default, pretty well still means "Reduced" in my experience.

Neo.cmg · Dec 9, 2007, 01:54 PM

I believe those options in the Energy Saver System Preference pane are unique to Apple's portable line of computers (both PPC and Intel). However, they are not present in the Mac Pros.

svtcontour · Dec 9, 2007, 02:00 PM

Intel's Speedstep technology maybe? Thats my guess.

zeropoint · Dec 10, 2007, 05:53 AM

I just discovered that the Santa Rosa chip in my MBP 2.4 was not stepping at all. My result in Core Duo Temp was the same i.e locked at 1.33ghz regardless of load. It seems that a number of others are affected in the same way. I crosschecked in
Xbench and sure enough my cpu test was way under half of other's tests. I installed Coolbook to try and prove what was happening and everything started working as it should. Xbench cpu result of 120.2 as opposed 41.2 previously.