The 5600 can get toasty, but will PBO itself quite well, if you give it good temps. I have 5600 (non X), and it boosts to 4.65 Ghz on all cores during benches and gaming. This is with a D15s (2 fans). Temps are 71c-ish during Cinebench in a non-AC room. Tried manually overclocking to 4.8 Ghz...temps shot up to 80C lol.