No way was it the 8600. I heard that it could go to about 890MHz with a volt mod, but I'm not exactly comfortable with volt mods. Most people aren't.
Ok, I have a question. For eg., if a 4850 can withstand heat upto 110C, and it goes to 70C on load at 700/1100, can you keep increasing it till it comes to about 100C load with something like 1000/1400? Only for benchmarking of course.