[CentOS] sempron 2500+ running at 1044 cpu speed.

On Thu, 4 May 2006, Andy Green wrote:
> I guess there is trouble with the kernel module (which is actually part of 
> the monolithic kernel for Fedora anyway) that does cpuspeed for your brand of 
> CPU.

powernow-k7 is a built-in module in CentOS-4. I had the same problem on my 
laptop, it ran at ~800MHz rather than 1666MHz (the normal frequency for 
this XP-M 2000+). Kernel messages indicated that it is a problem that is 
fairly common:

---
powernow: PowerNOW! Technology present. Can scale: frequency and voltage.
powernow: No PST tables match this cpuid (0x781)
powernow: This is indicative of a broken BIOS.
powernow: Trying ACPI perflib
powernow: ACPI perflib can not be used in this platform
powernow: ACPI and legacy methods failed
powernow: See 
http://www.codemonkey.org.uk/projects/cpufreq/powernow-k7.shtml
---

The strange thing is that on this laptop powernow-k7 also succeeds 
every now and then:

---
powernow: PowerNOW! Technology present. Can scale: frequency and voltage.
powernow: SGTC: 13333
powernow: Minimum speed 799 MHz. Maximum speed 1666 MHz.
---

I haven't decided yet whether I will ditch this driver or not. But it is 
not really urgent when I don't need Eclipse for the day :).

-- Daniel