What are you doing that needs that much cpu power
Who me? Game design and gaming, every little Mhz I can squeeze out will help me
not in rendering but just making the app smoother.
Above 4.5Ghz I don't see the point in increasing the voltage and in term increasing temps to get another .2Ghz it's not warranted. My temps jump from 60C CPU @ 1.345v @4.5Ghz to 74C for only .2Ghz more.
Unless I really needed it, I would do it but its not going to do to much of an upgrade.
I can't wait till Ivy Bridge-E or Haswell, I'll finally be able to get a consumer grade 6 core for under $500
the more cores the better for rendering, gaming it's not really going to matter as I have a GTX 670.