When i plug in any devices (mouse, keyboard) into usb 3.0 system dell n7110 overheats and fan goes crazy with terrible noise.
So i'm using 1 usb 2.0 slot now with a usb hub. It doesn't solve the problem completely but system stays at a low fan rate for a longer time.
I've tried to lower CPU frequency, but in my case (DELL INSPIRON N7110 i7 on Linux 3.0.0-14-generic #23-Ubuntu SMP Mon Nov 21 20:28:43 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux) CPU was pretty cool (51 C) and still the same horrible fan noise.
Looks like there is no such problems with ubuntu 10.04 (but there're some other problems).
Ubuntu even doesn't boot if anything is plugged into usb 3.0