There is a guy on TPU with his E5640 at 4.4ghz killing a 3960X in single thread and almost matching it's 6 core 12 thread multithread performance. You can OC the 3960X though.
No you see you said the i7 920 won't handle it, the E5640 is the exact same CPU as the 920, just has more cache and is on a more efficient process, also code names Westmere-EP.