[ltp] CPU Speed / Intel Speed-step {fix}

[Mendel Cooper]

This must have been discussed here before, but I probably had
other concerns at the time. . . .

Anyhow, with Pentium 4's, and possibly late-stage PIIIs, Intel's
"speed-step" technology slows down the cpu speed on the laptop
computer when running on battery. When running connected to AC,
however, you'd normally want the laptop to run at full rated speed.

As of the 2.6 series Linux kernel, speed-step is natively supported.
That's the good news. The bad news is that in some distros you have
to enable it.

Example:

On a TP A31, running FC4 (using AC power):

$ cat proc/cpuinfo

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 2
model name      : Intel(R) Pentium(R) 4 Mobile CPU 1.60GHz
stepping        : 4
cpu MHz         : 1199.0


Uh, oh. Not running at full speed!

However . . .

Making a small change to /etc/cpuspeed.conf

# uncomment and modify this to check the state of the AC adapter
OPTS="$OPTS -a /proc/acpi/ac_adapter/*/state"
OPTS="$OPTS -C"



Then . . .

$cat /proc/cpuinfo

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 2
model name      : Intel(R) Pentium(R) 4 Mobile CPU 1.60GHz
stepping        : 4
cpu MHz         : 1598.742



Problem fixed.


I hope this is of help to someone.



Mendel