Originally Posted by Apokalipse
A typical "450W" PSU would, but not this one.
Also, the 5870 has really good performance per watt. It will use 188W under full load, and less than 30W idle.
The system in total (including CPU) will probably use about 350W total under full load (CPU + GPU)
Well below the PSU's ability to continuously supply at least 450W
A crap PSU rated at 450W might only achieve 450W peak under ideal conditions (i.e. not the conditions you'd use a gaming PC in), so one of those might have problems with this build using about 350W. The corsair VX-450 is miles ahead of a crap 450W PSU.
That Corsair PSU has 33 Amps on the 12v rail.
A full system with a 5870 draws around 350 watts at load.
If you overclocked the 5870 and the CPU I'm pretty sure the PSU would start to feel the heat, unless the 450w Corsair is capable of providing more than what it's spec is rated for.
I wouldn't personally risk it, despite Corsair's good reputation, and their top tier PSU's.
That's closer than I'd personally like to cut it.