Power Consumption
Alright, so, I’d argue that neither the Radeon HD 7770 nor the 7750 push mainstream graphics performance up at their price points. You can already buy a 256-bit GeForce GTX 460 or Radeon HD 6850 for what AMD plans to sell the 7770 for, and both of those boards are, on average, faster.
These cards do have a profound impact on power, though. That much is obvious from their TDPs, dimensions, and auxiliary connectors.
At idle, sitting on the Windows 7 desktop, our overclocked Core i7-3960X-based machine shows both Radeon HD 7700-series chips cutting system consumption by 6 W compared to the GeForce GTX 460 and 560 Ti. AMD’s older Radeon HD 6850 uses 10 W more.
And then you’re able to factor in ZeroCore, a collection of power-saving technologies that kick in as soon as our test platform’s display switches off. Cooling fans stop spinning, clock rate drops, and on-board memory goes to sleep. The result is a further 6 W shave down to 84 W total system power on both 7700s.
The competing cards, on the other hand, don’t manage to cut consumption by much at all (1 W in a handful of cases).
The above graph is what this story is all about. AMD isn’t hitting particularly amazing price points, it’s not doing anything amazing for performance, but it is doing everything that the previous generation of cards from both companies could do at significantly lower power. As a result, efficiency improves and you get a lot more performance per watt consumed.
