This is my first mining rig that I build.

Spec:
Gigabyte Intel Z77 LGA 1155
Intel Celeron G1620 2.70GHz
(2) Kingston Hyper X 4GB
SanDisk SSD 32GB
Enermax MaxREVO 1350Watt Gold Plus
(4) Sapphire R9 270x Vapor-x
(4) 1x-16x Riser
Window 8.1

The mining rig will run about 45min-90min than it will shutdown/black screen. I also hear my GPU fan making louder noise when it goes black screen. I'm using a custom build open air case and using a box fan to cool it with windows open.