So a friend of mine upgraded his Pc rig and gave me some of his old stuff. I got an AMD Radeon HD 7870, a Fractal Core case, an EVGA 500w PSU, a Gigabyte motherboard for LGA1155 (so Sandy and Ivy bridge CPUs) and a monitor. All I need is a CPU and some ram and a hard drive. The cost of a used i5-3570k, 8gb of ram, and a hard drive adds up to about $300 Then I was thinking, I have 2013 iMac 21.5" (i5, 8gb, GT 750m), is it possible to get a thunderbolt adapter and just use the 7870 with the iMac? I'm gonna be running on windows 8.1. Also could I use the internal iMac display?