I was given an old Mac Pro 1,1 with 32 GB of FB-DIMMs and two dual core CPU. I was able to source 2 Quad Core Xeon X5365s and a ATI Raedon 5770 on the very cheap (practically free). With this setup, I was able to install OS X 10.11 El Capitan using Pike R. Alpha's boot-loader - http://piker-alpha.github.io/macosxbootloader/
Would anyone know if this would be a viable system for Folding@home? I know power consumption would be an issue, but that's about it. Thanks in advance for the comments.