Shemz Boss :
anti-duck :
At those resolutions a 750Ti would get the most out of your games. But a good quality 450-500w PSU would be a really nice upgrade. The XFX Pro Core Edition 450w would be an awesome choice, but I don't know how far you might want to go with the GPU.
So, do i need a new PSU for 750Ti? or will it go fine with the one i got? Also, is R9 270 alot better than 750Ti or only a bit?
You shouldn't need a new PSU but you might be cutting it very close depending on the quality of your PSU, I saw the 750Ti consume 221w in a top of the range system.
The R9 270 isn't massively better, but it'll definitely be noticeably better.
Oh, forgot to add that the R9 270 is only ~£20 more than the 750Ti for a very nice performance boost, but bear in mind that you would need a new PSU.