On Tue, May 10, 2011 at 9:38 AM, Bill Longman <bill.long...@gmail.com> wrote: > On 05/10/2011 09:34 AM, James wrote: >> Alan McKinnon <alan.mckinnon <at> gmail.com> writes: >> >> >>> otherwise. Just enable ondemand, disable everything else, and et the kernel >>> get on with doing what it does best: >> >> So this is what you are saying? >> >> >> [*] CPU Frequency scaling │ │ >> │ │ [*] Enable CPUfreq debugging │ │ >> │ │ <*> CPU frequency translation statistics │ │ >> │ │ [ ] CPU frequency translation statistics details │ │ >> │ │ Default CPUFreq governor (performance) ---> │ │ >> │ │ -*- 'performance' governor │ │ >> │ │ < > 'powersave' governor │ │ >> │ │ < > 'userspace' governor for userspace frequency scaling│ │ >> │ │ <*> 'ondemand' cpufreq policy governor │ │ >> │ │ < > 'conservative' cpufreq governor │ │ >> │ │ *** CPUFreq processor drivers *** │ │ >> │ │ < > Processor Clocking Control interface driver │ │ >> │ │ <*> ACPI Processor P-States driver │ │ >> │ │ < > AMD Opteron/Athlon64 PowerNow! │ │ >> │ │ < > Intel Enhanced SpeedStep (deprecated) │ │ >> │ │ < > Intel Pentium 4 clock modulation >> >> > > Yes but no. Yes, those are the correct choices, but the default governor > should be ondemand.
Or in the case of the OP who is brave enough (or silly enough?) to risk the long term reliability of his CPU running it with no fan, possibly choose powersave with a specific low clock rate as the default and then switch to either ondemand or conservative manually when he needs more performance. In a machine such as he's playing with I wonder if he really wants ondemand (jumps to max and then slows down over time) vs conservative which more slowly ramps up the clock rate if the job at hand takes more time. It's all a trade off of performance vs power & heat. On my 12 thread server I've played with these two and frankly don't see a lot of difference doing any large job. They are both a bot slower than running performance, but I save a lot of power (and over time money) using them so I'm happy. - Mark
