It seems to run at the same temps on any vcore setting. At 1.2 volts it runs at ~45 idle and up to 70 on load. It runs exactly the same at 1.35, where it can be OC'd to 4ghz stable.
I replaced the heat stink a few times, and I just replaced the thermal paste but it hasn't helped. It's just gotten really quite warm in my area (90 F, a little humid) but it was still running hot before that.
I just reapplied thermal and remounted the heatstink again and I'm idling now at 39, 44, 42, 39. So I may have dropped a few degrees.. it may go down a bit further when the thermal paste gets situated?
I spiked to 72 degrees while playing a game and it worries me a bit. My ambient temps will frequently be like this as my family is too cheap!!! hehe. I mean, I want the chip to last at least 2-3 years..!
I pull the board to replace Intel heat sinks. It assures proper seating of the pins. I also "stagger" pin insertion.... ie: opposite corners vs doing it in a clock wise manner. This ensures a more uniform contact.
I also use Thermaltake Duorb's. ( there are some boards these won't work on.... XFX for one because of a large capacitor ). Best for the job and don't warp your board like Zalmans and are much quieter than the one you're using. My 9550 runs at 37c under true load.