I use a Intel i7 Dell-laptop. I installed Ubuntu 12.04(64bit) from scratch. I realized the CPU temperature increased immediately(it's not difficult to detect temperature with this computer only by hand) . When I played flash players in youtube or elsewhere I saw in the system manager that only one core increased working frequency despite all other. And that core was like 80-90% while the others stayed at 5%. Any suggestions? Should I install 32bit version of Ubuntu?