My MSI 7970 does not run hot if overclocked (mine is a reference design- 1 fan rear exhaust) I'm at 1090 stock voltage (but 75% fan speed - i've always used ear phones so the noise doesn't bother me and get avg 50-55 degrees - so its up to you once again whether noise is a problem - but heat definitely isn't if you raise fan speed).
If your into overclocking then,
1. 7950 OC can match/beat 7970 stock.
2. But if you are willing to OC 7950, then your also going to OC a 7970 (right?). Which means,
3. 7970 OC beats 7950 OC easily
(unless i'm wrong and the 7950 can OC to 7970 levels, then please inform me). Many ppl seem to hit 1125hz+ easily without voltage increase [ i just got a *** card]).
Depending on a number of factors:
- Your rig (CPU/etc)
- Games you play
- How willing/pissy you are on dishing out extra money for 7970 based on,
===>Most importantly (in MY opinion, when it comes down to buying graphics cards) ==> what average fps "YOU" want, will determine what card you should get.