7870 CrossFireX Power

Hi guys. I want to build a gaming PC soon and I want to spend just a bit less right now and spend more later so I was thinking of buying a single 7870 right now and then later buying another to Crossfire it. I wanted  to know what the wattage of my PSU should be. Just to play it safe, I'm planning on getting a Rosewill Hive 750W on Newegg. If you need to know my Motherboard I plan it to be a GIGABYTE GA990FX-UD3 AM3+ with a AMD 6300.

Thanks for any feedback. It's appreciated.

750 watts will be fine. You may be able to Crossfire with 650 watts.

I agree. 650 watts most likely run it well but if you plan on overclocking I think it would be safer to stick to a 750 as long as you're not going too oiut of budget.

Thank you guys. I dont plan on overclocking as my technical skills aren't ready for that, but I may do it later on when they improve and I have the "know how."