I used to be able to overclock and underclock my 701 (Celeron) by
using /usr/local/cpu-freq/cpu_freq and then loading the p4_clockmod module in the UI
The P4 clockmod has always been incompatible with the Eeepc 701 celeron even in the original Xandros OS. There is extensive documentation of this in the eeeuser wiki, the eeeuser forum and in various threads in this forum.
The various scripts and applications that were made for Puppy on Eeepc 701 & 900 series with Intel Celeron M353 processor do not utilize the P4 clockmod at all. Much testing has been done on these "clocking" scripts. In Puppy Linux the various apps that were put together for cpu control rely on an eee specific driver compiled for Puppy Linux by tempestuous. It is of course incompatible with the P4 clockmod. Similar utility applications for Xandros and Ubuntu relied on eee specific drivers compiled for those platforms. I have used those myself and found that they are incompatible with the P4 clockmod.
When the P4 clockmod is loaded it will report that the cpu is clocking at 900MHz. However it is not clocking at 900MHz since the fsb remains at 70MHz.
A quote from the eeeuser forums (
http://forum.eeeuser.com/viewtopic.php?pid=19749#p19749) to demonstrate my point:
My points regarding ODCM are unrelated to the FSB's impact on the actual operating frequency. When I stated that "the processor frequency never changes" it was in regards to ODCM throttle states not being capable of altering the CPU frequency. I was not stating that the processor runs at 900 MHz irregardless of FSB frequency (that statement would not be in line with the 'published' CPU theorem that I worked so hard on big_smile)
Back to ODCM:
When somewhat idle various Linux utilities on the eeePC would report that the processor is running at 112.50 MHz (12.5% throttle), such a reported frequency is incorrect because of the following reasons:
1- The utility incorrectly assumes the FSB is 100 MHz. Since the FSB is running at 70 MHz the CPU is actually running at 630 MHz therefore a 12.5% ODCM throttle should be reported as 78.75 MHz CPU frequency.
BUT more importantly the 78.75 MHz CPU frequency is still incorrect because...
2- ODCM throttling does not alter the CPU's operating frequency.
All in all, due to p4_clockmod and cpufreq modules the CPU frequency reported in linux/Xandros is always FUBAR
This remains true of other linux distros (bios issue not OS problem). The various utilities in Xandros, Ubuntu and Puppy Linux to mention a few work by adjusting the fsb from 70MHz up or down the scale to achieve the desire cpu performance.
Quote from an eeuser forum thread (
http://forum.eeeuser.com/viewtopic.php?id=65557&p=2) I started discussing a very simple gtk dialogue gui script that I had written to give user control over various cpu controls including fan speed and cpu over/under clocking. This is from one of several user tests regarding battery life.
900MHz: 2h37m
630MHz: 3h17M
360MHz: 3h06m
Testing done by Wegan Warrior and Jakfish with respect to battery life showed result inconsistent with expectations.
900MHz: 2h37m
630MHz: 3h17M
540MHz: 2h49m
450MHz: 2h52m
360MHz: 3h06m
Here is a quote from that same eeeuser thread regarding testing of battery life at various speeds.
Many, many thanks for doing this. Your results are so startling, but I got pretty much the same numbers with 360MHz vs. 630MHz.
Below 360MHz can run a user into instability issues, I think, though when I used CPU scaling_frequency, I set the range between 100MHz and 70MHz without ever crashing.
The trouble w/ scaling_frequency, I didn't see any positive effect to battery life and the lag (when it's idling at low speed and must regroup itself to launch an app) was vexing.
Your tests show that underclocking, at least in Linux, is unnecessary. I wonder if you could get the same results in XP//eeectl.
Jake
There are a couple of other threads on the Puppy Linux forums where these same issues were discussed and worked out resulting in an application originally written by tempestuous that was far more advanced than the little script I wrote. That work was picked up on and advanced by 01micko (I believe, correct me if I am wrong). It resulted in an application that worked on Eeepc models with Celeron and Atom processors.
The cpu control utility in Puppeee as developed by Jemimah function by adjusting the fsb to achieve the desired results as well. It would seem fruitless and possibly harmful to the eeepc to load the P4 clockmod module in an attempt to control cpu speeds.
