as far as i've read on the internet, gtx 295 consumes less power compared to 4870x2. it dissipates heat far far lesser than 4870x2.
the 4870x2 is like an oven.
but, thats what i have read. if you can w8 till june, im heading off to buy a gtx 295 around that time & then i can tell you my own personal experience with that card. but yes i have already tried 4870x2. its hot. i need to keep my side panel open at all times if im to play assasins creed or crysis warhead with 4870x2.
im actually waiting for ati to release their 5800 series. love to see how hot those would run. lol.