An athln ii x2 clock for clock is roughly equivalent to a core2, and since the 270 is clocked higher it will have an advantage. The pentium G2020 is Sandybridge based and is better clock for clock, this article explains it pretty well http://www.tomshardware.com/reviews/ivy-bridge-wolfdale-yorkfield-comparison,3487.html. If you are planning on upgrading, you should probably look at both a better core for core performance and more cores, at least a phenom ii x4 or higher so that there is a more noticeable difference.