Re: Amd Gaming build with a twist.
some of the MSI boards (the 890fxa-g65 specifically) also supports bulldozer. they snuck in an extra pin for bulldozer.
the psu will be fine for crossfired 6970's, it's 80% efficiency stood up under tests, they used good quality components in it, so I wouldn't worry about it, but if you haven't bought it yet then I'd go with one of slay's suggestions. While the XFX is a fine psu the corsair is just better.
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