Red Hat Bugzilla – Bug 438961
CPU frequency scaling unsupported
Last modified: 2008-04-03 10:34:13 EDT
Description of problem:
CPU frequency scaling does not support intel PE 2180 on a Nvidia 650i MB
Version-Release number of selected component (if applicable):
Steps to Reproduce:
Please provide the contents of /proc/cpuinfo and a dmesg dump from a fresh boot
with cpufreq.debug=7 added as a kernel boot parameter.
Created attachment 299438 [details]
i add cpufreq.debug=7 as as a kernel boot parameter then i find the file named
cpuinfo under /proc, but it's 0byte file
i upload a copy of dmesg.
why is cpuinfo 0byte file ?
help me to solve then i will upload it.
Hrm... I'm not seeing any evidence that the cpuspeed service is starting up. Do
you have the cpuspeed package installed, and if so, is it starting on boot?
Quick check would be to simply issue the command:
/sbin/service cpuspeed start
The output from that (or lack thereof) ought to shed some light, I think.
As for the 0-byte /proc/cpuinfo... No clue how that could happen, but it doesn't
sound particularly good. Just had another thought... The cpuspeed init script
actually keys off some info in /proc/cpuinfo these days, so if you don't have
it, that could actually be part of why freq scaling isn't getting set up.
I don't suppose there's a bios update available for your board that might also help?
I freshly install fedora 8 and fedora 9 beta,keep all default, then reboot
after "firstboot", it pop-up a window showing:"CPU frequency scaling
After that i follow your instruction and get the cpuinfo, i donn't know where
the fault lies
i check the "service", make sure of CPUSPEED start up in level 3,4,5
sorry for my english, it may suck.
Okay, if you get 'CPU frequency scaling unsupported', then the acpi-cpufreq
driver doesn't work with your processor. Best as I can tell, a PE2180 processor
is a Pentium 4-derived dual-core cpu (possibly in the Pentium D line), so I
believe we're actually doing the right thing here.
You might get cpu throttling using the p4-clockmod driver, but for various
reasons, the p4-clockmod driver is terrible so we don't enable it. There's a
comment in /etc/sysconfig/cpuspeed that points here for some reference info on
If you find evidence this processor actually *should* be supported by the
acpi-cpufreq driver, then the fault probably lies with the system's BIOS. In
that case, it might be worth finding a BIOS update, but I'm pretty sure this is
simply a cpu that doesn't support sane cpu frequency scaling.
My bios is the newest.
i donn't think it's a problem of neither CPU nor CPUfreq driver, i think it's
motherboard's problem cause im-sensors cann't detect any sensor,but GPU, located
in my MB
My MB is a nvidia 650i chipset, which is not as popular as another intel or
nvidia chipset, so it might not be supported well enough
i assume it will solve in next release after Fedora 9
god bless :)
Still reasonably certain this is either a bios bug or a case of a cpu that
doesn't support real cpu freq scaling, since its P4-based. For now, I'm going to