Just thought I'd note this here in case anybody's having similar issues...
I'm putting it in the folding forum because I'm not sure anybody else at SPCR would have a good reason to try and run their CPU at full whack all the time.
My work machine is a Dell Precision M65 notebook. I've been running the Windows SMP client on it. By chance, I happened to be running CPU-Z a few days ago and discovered that the processor was stepping down from 2000MHz to 1666, 1333 or even 1000 whilst F@H was running.
Now, this shocked me for two reasons:
1) I had assumed that the processor would run full speed if fed with work by processes like F@H.
2) I thought I had set the machine to run at "High Performance" when on AC.
I thought maybe the F@H processes were set at too low a priority to keep the processor at full speed, so I increased the priority. No good, it was still stepping down. "Grr! Stupid windows," I thought...
So off I went and learned about the windows command-line power management utilities. All well and good, I set the thing to "none" for cpu stepping on AC, assuming that'd solve the problem. No such luck. In theory, the settings were fine, but in practice, it was still inexplicably stepping down...
So when I was at work today, I was thinking about it all and fired up cpu-z again. Then I noticed that the thing wasn't throttling anymore. Sat solid at 2000MHz for hours. Then I realised, the laptop sits raised 4" on a perforated steel laptop stand at work, but flat on my wooden desk at home. I came home and raised it up by putting a 1/2" book under each corner and bingo! no more throttling (incidentally, I recommend the ExpressExec
series of management books for this purpose - they're bloody useless for anything else).
So it looks like, even in a fairly cold study, the Precision M65 needs extra airflow to the intake at the bottom of the machine to cool itself properly. Surprising, since the rubber feet already lift it a good few mm off the surface. I'm tempted to take it apart and clean out any dust before reseating the heatsinks with some good thermal compound, but I don't want to screw it up, since it belongs to work, not me! I've downclocked the GPU, since I understand it uses the same heatsink as the CPU.
I'm not overclocking it and it's not very old. CPU/GPU overheating could explain some instability I've been suffering from time to time, as well. Not too impressive for what's supposed to be an engineering workstation.