I'm looking to upgrade the CPU in my budget play-this-till-I-get-a-job-and-build-a-monster PC and am curious if replacing the stock AMD athlon II X4 640 with an Intel Core i5-4590 would give me a decent increase in performance for CPU heavy games like Total War: ROME II. At first I thought upgrading would be a no brainer but then i discovered that my stock CPU actually costs MORE! So tell me what I'm missing here because I don't know too much about what makes a CPU good.