Quote Originally Posted by Chumbucket843 View Post
1GHz 5870 would use ~250 watts if we interpolate what the 4890 was to the 4870. its the same reason netburst didnt work. ramping up clockspeed is terribly inefficient and very few chips can be binned that high with out a silicon revision. 5950 sounds much better imo.
Gotta read this - hilarious Intel VP

Yup.

That's why 8800GT (600Mhz) runs at 1.05V and 9800GTX (738Mhz) at 1.15V.
Both are much lower than Intel, and especially AMD CPU (ie 1.35V).

As you said, its combination of good avg clockspeed at min voltage in order to keep power in check. Beyond a certain clockspeed, agressive exponential increase in voltage is needed for stability. As you may imagine, power skyrockets ( ~dynamic powa = (V^2) * C * Mhz ).

Which brings up an interesting point - GTX480/Fermi overclocking... probably very little to no headroom.
1. Would need extra power connectors.
2. Heatsink cooling doesn't scale linearly with size. Once you already have dual slot heatpipe cooler, making it 50% bigger doesn't improve cooling 50% - diminishing returns.
3. Modern high end GPUs are already running 80-90C, with VRM/MOSFET temp of over 100C not uncommon. Fermi overclocking - Do you really want to set fire to fluffy your plush rabbit (sitting on your case)?