I'm looking to purchase a used Mac Pro. I have a very limited budget and would like to get some advice on Mac Pro options between 3,1 and 5,1. I see some systems with higher proc speed on older systems. More/less cores and wildly divergent prices. If I were to purchase an older say 3,1 from 2008 with similar proc and ram vs say a 2010 5,1 what are the performance implications if I install the latest OS on either and doing some basic graphics and video with Adobe products?