Hey guys what size PSU would I need for 2 x 270s and 2 x 7870s? (total 4 gpus)
Rest of the rig is:

Athlon II X2 240
Asus M5a97 Le R2.0
4gb DDR3
1 7200rpm HDD

I tried with a few calculators online but they're throwing something like 650W which I think it's too low, isn't it?
Do you think a 850W psu will do?

Appreciate your help guys, cheers