Samy60, if you have a dedicated Folding machine (as in you never do anything else with it) I would install Ubuntu and not chance Windows. Just a personal opinion as the Ubuntu 14.04 LTS machines I have here are rock-solid and will Fold unattended for months at a time. I do go and apply updates from time-to-time but since these are behind the NAT Router, I'm not too worried about Internet attacks.
I also found that I could install the CUPS service on my old Mac Pro running Ubuntu and now all my iOS devices can print to my old LAN-connected printers. I had spent $99 for the Lantronix xPrintServer but it couldn't deal with my Canon 4700 Copier/FAX/Printer/Scanner which is located downstairs in the family computer area. The few times that we use it means it isn't tying up the host with print processing.
I guess I could also install Plex or a DLNA media server, but I'd rather set up a separate box for that. Now that I have the Hopper 3, I might revisit that possibility.
I've been looking at my numbers and I would if the GTX 750i might not do better in the T7400 and not the Mac Pro. I was investigating the Mac Pro's PCI-e slots and evidently the Slot 3 I had to use is only 4x and not 8x line Slot 4. Unfortunately, I can't plug a double-wide card into the last slot, so the card isn't running as fast as it could. Mechanically, all the slots in the Mac Pro are x16, but electrically only Slot 1 is x16. The T7400 has an unused x16 slot available, and it's x16 electrically as well. Plus, that changes my CPU Slot to 6-core instead 7-core, and that would open it up to some Projects that aren't compatible with 5, 7, or 11 cores. 3 seems to be okay, so my Mac Pro's older CPU slot might benefit.
Edit: I just looked at the EOC site, and I see there's a new sheriff in town: