I installed Mandrake 10 official to Dell D600 laptop(Pentium M 1600Mhz), it runs just fine and I like it.

However, I found sometimes the CPU freq is shown only at 600Mhz(instead of 1600Mhz), I'm using the 2.6.3 kernel:

$uname -a
Linux joyhaa 2.6.3-7mdk #1 Wed Mar 17 15:56:42 CET 2004 i686 unknown unknown GNU/Linux

$cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 9
model name : Intel® Pentium® M processor 1600MHz
stepping : 5
cpu MHz : 599.640 <----?????
cache size : 1024 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 mce cx8 sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 tm pbe tm2 est
bogomips : 1187.84


any insights?

TIA

Check the file /proc/acpi/Processor/CPU0/throttling

See what you have in there. I'd be willing to bet that your cpu has been throttled inadvertantly. Post the output of
here so we can see this file. If it has been throttled, there's an easy fix for it.

here is the output:

$cat /proc/acpi/processor/CPU0/throttling
state count: 8
active state: T0
states:
*T0: 00%
T1: 12%
T2: 25%
T3: 37%
T4: 50%
T5: 62%
T6: 75%
T7: 87%


$chkconfig --list | grep cpi
acpi 0:off 1:off 2:on 3:on 4:on 5:on 6:off
acpid 0:off 1:off 2:off 3:on 4:on 5:on 6:off

i did see 1.6Ghz on /proc/cpuinfo a couple of times before...wierd

thanks.

ok, i figured out how to fix it:

vi /etc/init.d/acpi

add "speedstep_centrino" to MODULES list(the 10th line).