I have an old T43 laptop by IBM. Recently I put Ubuntu 8.04 (Hardy) on it and started getting a hissing noise when running on battery power. I found 2 possible solutions:
- add the following to /etc/modprobe.d/options
- options processor max_cstate=2
- get the linux-server kernel
- sudo apt-get install linux-server
I didn’t get a chance to try the first option as I already put the linux-server kernel on there. If the first one gives you any luck write a comment and let me know.