Soleron on 21 December 2012
The four 12V rails are really one 12V rail. Even if that wasn't the case, there are two power connectors from the card and they can go on different rails. The requirements are high because of poor quality PSUs that don't provide the stated power, but your whole system power consumption with the GPU loaded won't exceed 400W; the GPU alone won't exceed 200 probably. It should be fine.
