Messages in this thread | | | From | Wes Felter <> | Subject | Re: em64t speedstep technology not supported in kernel yet? | Date | Thu, 29 Sep 2005 13:58:18 -0500 |
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Richard Wohlstadter wrote: > Hello all, > > We recently had Intel give our company a roadmap presentation where they > told us that their enhanced speedstep technology was supported by linux > kernels 2.6.9+. I have since tried to get cpufreq speedstep driver to > work with no luck on our em64t Xeon 3.6g processors. Intel even has a > webpage describing the technology and how to get it working at url: > http://www.intel.com/cd/ids/developer/asmo-na/eng/195910.htm?prn=Y
I think this is a BIOS problem; the BIOS needs to provide the proper ACPI frequency/voltage tables for cpufreq to use. You might want to harass your system/motherboard vendor.
Alternately maybe you can find someone who can give you the secret table and then you can just hardcode it into the driver.
> The only processor I have had luck with so far is a 32-bit Xeon with the > p4-clockmod driver(which does not appear to be present in the x86-64 > kernel).
Beware that p4-clockmod won't increase the power efficiency of your system. (As an aside, clock modulation is so simple that you can do it from userspace in a few lines of C if you modprobe msr. This works on x86-64.)
Wes Felter - wesley@felter.org
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