Tri-fire HD7970x2 with 280x PSU wattage

[bowzef]

i'm up in the air on how much power i'l need for a tri-fire setup i was given a free 280x , so i'm not sure if 1000w or 1200w is needed as i'm going be overclocking my CPU a i5 4690k with corsair h100i to around 4.5ghz to 4.7ghz

would Corsair Rm 1000w be enough? or would something like silverstone 1200w gold evolution St1200g PSU be better choice? they are around same price, i don't wanna spend more then $300 Australian

 

[MeteorsRaining]

Atleast a 1200W would be desirable, avoid RM 750W and above models, they're low quality, Strider Gold is much better quality wise. Also, if you can afford it, this would be better than both the ones you've mentioned:
Power Supply: XFX ProSeries 1250W 80+ Gold Certified Fully-Modular ATX Power Supply ($322.00 @ Mwave Australia)