On Mon, 2006-10-02 at 12:01 -0400, Dave Jones wrote:
On Mon, Oct 02, 2006 at 09:45:27AM -0400, Thomas J. Baker wrote:
> I've got two questions related to cpu scaling. On my laptop I've got a
> Core 2 Duo. Can the two cores scale frequencies independently?
No. Think about it. You have a single package, with a single power source.
> Most of
> the time that doesn't seem like the case but every once in a while, my
> cpufreq applets show different speeds. I'm assuming that there is just a
> bit of slop involved and the two cores are always the same speed.
It's a bug, but it should be cosmetic only. It's on the TODO, but
there are a number of other issues in this code that need tackling
first before it gets clean enough to fix this properly.
> On my desktop, I've got Xeon CPUs that support limited scaling; they run
> at either 2.8 or 3.4GHz. On FC5, they used to scale on demand but under
> FC6 they don't and the cpufreq applet has a manual setting for 2.8 or
> 3.4 with an automatic setting that is greyed out.
Which cpufreq driver were they using ?
File a kernel bug, and attach dmesg.
Just curious - it must also a bug that under FC5, with two hyperthreaded
Xeon CPUs, all four logical processors scale independently?
I looked at my FC5 setup and had specified "DRIVER=acpi-cpufreq"
manually. Doing this for FC6 made the scaling behave like FC5,
automatically scaling up for load.
| Thomas Baker email: tjb(a)unh.edu |
| Systems Programmer |
| Research Computing Center voice: (603) 862-4490 |
| University of New Hampshire fax: (603) 862-1761 |
| 332 Morse Hall |
| Durham, NH 03824 USA http://wintermute.sr.unh.edu/~tjb