I assume that when u are considering cf u have a) pci-e gen 2 x8 x8 setup. b) 4 6-pin pci-e powerconnectors
Crossfire has improved with current drivers but be prepared for some hiccups at times esp with new games until a proper cf profile is up.
Dual 7950 is still more powerful than any single gpu (when it works) except maybe the GTX 980.
If u are worried abt the heat consumption use vbe7 editor to undervolt the card. (At the same time u can equalise both cards gpu speed). Amd stock voltages (esp boost volts) are ridiculously high. U can actually under-volt by a massive amount. In addition, 7950 have dual bios so u can easily recover if you screw up.
for example,
my 7950 actually has a massively undervolted setting (max load power consumption is slightly higher than 7850; <150W TDP).
it can run at 800 (GPU)/ 1350 (RAM) at 0.925V.
Currently its running at the undervolted/ overclocked setting of 1050/1350.
You can adjust based on your usage. Essentially your two gpu at full load (i.e. furmark) could run anywhere from <300W to 400W depending on you adjust the voltages. Real-life gaming usage would be less.
I don't have all my old statistics but i can give you an idea
Core/RAM speed Volt Load power (heaven)
800/1350 0.925 233
925/1350 1 251
1050/1350 1.15 337
This values was on an overclocked FX 8350. The stock boost volt for the 7950 boost is 1.25V
