I built this to be a multi-os monster. I have a evga 660 in sli with the gigabyte but the partpicker list only let me select one brand of videocard so i just listed 2 gigabytes. Also the Gigabyte z77x-ud3h mobo isn't listed so i left that out. I have 3 os'es but the partpicker list wont let me select all three so i will list them here. As listed i have Windows 8.1 pro, Ubuntu linux 12.04 LTS with Steamos installed on it, and mac os x 10.9.1 maverick. yep i've been busy. I game and spend time giving help in overclock forums. My main thing i do is tweak. i love to see how far i can push. I have the xspc ax240 watercooling kit plus another 240mm radiator. an added note the xspc radiator kits have really difficult to mount cpu waterblocks. Now updated to i7-3770k at 4.8GHz will be making a new rig for it.