This may be a stupid question, but I don't really know a huge deal about ram. I have a 4GB stick in my PC at the minute, it's 1.35v and 1600mhz. If I bought an 8GB stick that is also 1.35v and 1600mhz, would that make 12GB that the PC can use? Also, would this put an increased amount of stress on my PSU? (I mean a significant amount) As I've added a 750 Ti already, and the PSU is only 300W and came with the PC.