Originally Posted by
STaRGaZeR
Do you know why? In the 4870 its GDDR5 doesn't reduce speed at idle, it remains at 900MHz. If you have ever had a card with GDDR5 you'd know that it consumes a buttload of power at idle if the frequencies are not lowered. Example: at idle, 300Mhz vs 900Mhz does almost nothing if you're talking about GDDR3, but with GDDR5 you're talking about 40+ watts. You know why 4870 doesn't clock the RAM to 500MHz at idle? The screen flickers when the change is done, and unfortunately 2D/3D detection on the 4870 sucks ass, so they can't lower it. The 2D/3D detection is changed in the 4870X2, so they can clock the GDDR5 to 500Mhz without flickering in not desired moments. That's why you see the 4870X2 consuming only a little bit more than a single 4870 at idle, even having twice the ram chips and two RV770s. That's also why you see the tremendous difference between 4870 and 4850 at idle.
Be careful with what you say about GDDR5, it's fast but sucks power like if it was no tomorrow. And that's precisely what you don't want in a GX2 card.