For one, the RAM. The minimum for gaming is 1333, though 1600 is recommended. The 7770 is faster, cheaper, and consumes less power than the 550-Ti. You can also grab a 650-Ti for the same price as that 550-Ti. I'd ditch the sound card, and dump it into a higher tier GPU, perhaps a 7870, or 7870 Tahiti LE? The integrated should be good enough for the time being.