My friend has a OCZ ModXStream 700W 80PLUS (80% efficient) power supply and an HD 6870 1GB graphics card. He plays a lot of games on his computer. My friend's planning on getting a second HD 6870 1GB graphics card for his computer. Would my friend need to get a bigger power supply, or will the 700W power supply suffice? He has an i5-2320, 4 hard drives, and like 7 fans in his computer, if that helps.