I recently decided to switch to Ubuntu from Windows 7, and I've been having some problems regarding CPU usage. Any program I have running uses 40-50% of my CPU, which is way too much obviously. I'm running TeamSpeak 3, Terminal, and Firefox as we speak, and TS3's CPU% is around 45% steady, something called "Xorg" is always between 20% and 50%, changing a lot, and Firefox is switching between as little as 2% up to as high as 40%. Sometimes a process even goes up to 150% CPU. I'm using Xubuntu 12.10 now, but I've had the same problem when I used Ubuntu 12.10. I can't watch video properly, it's always lagging, and it's taking a long time to switch tabs in Firefox. I've been searching for the source of this problem for a long time but I couldn't find it, that's why I'm asking my question here.
My laptop specs are:
Intel i3 processor
AMD ATI Mobility Radeon HD 4500/5100 Series