Processor Scaling

Anthony M. Rasat anthony.rasat at
Sat Jan 3 04:29:23 UTC 2009

Ray Parrish wrote:
>I have discovered that my sytem has processor scaling, and most of the 
time my system is running at half speed. 
>How do I disable processor 
scaling so I can run at full speed at all times?

I have Everex cloudbook UMPC and enabling frequency scaling does doubling processor speed. Without frequency scaling, cloudbook is detected having 600Mhz and stays that way for whole time. But after frequency scaling compiled-ins, frequency may peak at 1200MHz. In Hardy, frequency scaling requires either kernel recompile from vanilla or using kernel backports.

After recompiling, to enable frequency scaling peaks its processor performance -- because you have desktop thus no need to conserve battery -- use following command:

sudo cpufreq-selector -g performance

However, processor cool-offs significantly when idle, which is perhaps a good idea for a desktop, using following command:

sudo cpufreq-selector -g ondemand  

Having ondemand method, processor throttles up when it needed processing power and throttles down when idle (which is almost always all the time).

But there is a caveat in cloudbook. Everytime ondemand frequency hits minimum 400Mhz, Hardy freeze solid. The workaround is to set minimum frequency to 500Mhz instead of 400Mhz.



Anthony M. Rasat
Manager - Technical, Network and Support Division
PT. Jawa Pos National Network
Graha Pena Jawa Pos Group Building, 5th floor
Jln. Raya Kebayoran Lama 12, Jakarta Selatan 12210
Phone 02132185562
Phone 081574217035
Fax 02153651465

More information about the ubuntu-users mailing list