Finally got my Karmic box working properly!

Ever since I upgraded to Karmic (9.10) my machine has performed like a dog - well as far as keyboard and mouse input went - the mouse would linger and the system would loose my keystrokes. I tried a bunch of things to no avail....

Then I was perusing the web - frustrated by my sluggish machine - I'd read about cpu frequency scaling and wondering if this might be an issue. Well it turned out to be the root of my problem! Though in general I think more modern CPU should operate fine with cpu scaling enabled but these old AMD Opteron CPU's don't seem to be up to it so I've disabled it and the machine behaves a lot better.

To fix it - firstly I installed the cpufrequtils:

sudo aptitude install cpufrequtils

Checked the current state of my machine (You can also do it using any of: cat /proc/cpuinfo, sudo dmidecode -t processor, lshw -C processor):

sudo aptitude install cpufreq-info

 My machine was in 'ondemand' mode - I changed it to 'performance' mode - for each of my two processors:

sudo cpufreq-set -c 0 -g performance
sudo cpufreq-set -c 1 -g performance

This is actually setting the following /sys entries: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor

There a few more things you can do with the cpufreq utils.

This driver is blocked due to incompatibility issues

Yeah this kept popping up and although it told me that the Driver: Virtual PC/Windows CE Emulator was the problem it firstly didn't tell me where it was (i.e. filename) nor how uninstall the damn thing?! (just some useless 'check for solutions online' button).

Finally I tracked it down using Microsoft's (was the excellent Sysinternals) LoadOrder tool and the very handy Autoruns. I tracked it down to: "VPCAppSv Provides application services for Virtual PC. Connectix Corporation c:\windows\system32\drivers\vpcappsv.sys" which turns out to be a black listed driver for WinXP. Nice.

So I just deleted from driver list (under HKLM\System\CurrentControlSet\Services) in Autoruns, then rebooted - and no more warnings ;) Then it can just be deleted.