Originally Posted by aiyaaabatt
Do you know if the SeaSonic 750X (Gold) PSU will be able to power crossfired (reference) r9 290x's at stock settings?
I know it is cutting it close, but also the Seasonic x750 is highly rated and has been tested to output 850w easily.
Am I running any risk by adding the second card? Hurry and stop me before I do it!!
850w is what it can manage for short periods of time, certainly not what it's recommended to do. It also depends on if you have a power hungry CPU, and if you're OCing it.
Two R9 290s output 250-300W depending on how heavily they're being used, even more wattage than 300W with OCing. Again, unless you have a power hungry CPU, the rest of your system including the CPU should be around 200W. So anywhere from 700-800W is what two should be drawing, assuming you aren't pushing them with OCing. If it was 675-775W, I would say you're fine, but that's a pretty close call and it isn't worth the risk.
I don't have a power hungry CPU, and I have a 750W PSU, so I'm considering not upgrading my PSU should the event arise that I need to upgrade (I hope it is a very long time from now), but even then I kind of want a 1000W just so I wouldn't ever have to worry. 750W was a terrible move in hindsight, I should have waited for a better deal on a 850W.