cpuinfo shows wrong MHz value

Joerg Platte
2009-02-14T21:48:11Z

I'm running kernel 2.6.28.4 and /proc/cpuinfo and powertop and vmware are
unable to detect the correct speed (1.6 GHz) of the processor:

cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 1
model name : Intel(R) Pentium(R) 4 CPU 1.60GHz
stepping : 2
cpu MHz : 13000.000
cache size : 256 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pebs bts
bogomips : 3197.21
clflush size : 64
power management:

According to dmesg the kernel detects the CPU correctly during bootup:

Enabling fast FPU save and restore... done.
Enabling unmasked SIMD FPU exception support... done.
Initializing CPU#0
PID hash table entries: 4096 (order: 12, 16384 bytes)
TSC: PIT calibration matches PMTIMER. 1 loops
Detected 1598.609 MHz processor.

IIRC this behavior started some kernels ago, I can't remember which kernel it
was. Is it possible that the ACPI information is wrong?

regards,
Jörg