Well, depending on the case that you have, if you put a gaming graphics card, airflow should be a factor. Dell normally puts tiny fans to bring in air. 2nd, you might bottleneck with a older CPU. Something nice you can add is a SSD
. Normally, Dell motherboards are so bad, that a gtx 770 card I thought was a good upgrade, messed up the whole computer. I suggest using the upgrade money, and save up for a nice build. It doesn't have to be 1500 or 2000$.