A little confused about the PSU requirement for the MSI R9 280X. It states I need a 750 watt psu and my current OCZ 500 watt is well below this. I've read that I won't need anywhere near as much as 750 but I'd rather just play it safe and go with what MSI say so can anyone recommend me a good 750 watt power supply. My budget is around £80 and I've been looking at the corsair cx750m. It fits my budget and seems to fill the requirements. Is this a good choice? Many thanks!