So ive got 4GB DDR3 1333mhz RAM from kingston in my pc, looking to upgrade to 8gb ddr3 1600mhz corsair vengeance ram! Is there a big diference, or should i spend this money on a better psu because ive got a crappy 1 and i'm going to upgrade itt to some decent psu!
It depends on what applications/games you're running. You can check the requirements for most of the games (as an example, the recommended memory amount for Crysis 2 is 2GB and for NFS 2012 is 4GB). Virtualization, video or photo editing require more memory. Increasing the RAMs will not necessarily increase the performance of the PC.
All I do at the moment is web browsing and play games, but i might to do some gameplays for youtube and i'll use fraps and it records short two minute clips so i have to put them together with a video editor, but that's about it!