zeyaa :
Could a 450W psu with 12V1 21A 12V2 18A power a gtx GTX760 or a R9 270X? Sticker on side of my psu: http://gyazo.com/2e9ece41f2d680ddae2c2ab203d20422
Hi - If that PSU can deliver it's rated specs, it is enough for a system with either of those cards. It
has barely enough +12v amps (30 total avail, not 39)for the gtx760 & has a little headroom for
an r9 270x. If you're gonna stay with that PSU go with the 270x because of the xtra +12v headroom.
Personally, I would start saving money for a better quality PSU. Lower quality PSU's often don't deliver their rated specs.
You don't need anywhere near a 750w PSU for a single GPU system. if you decide to upgrade in the near future,
a good quality 500-550w unit will provide plenty of power.