Since I knew people would ask... The frame is just 1inch square aluminum tube rived together with some flat / angled aluminum... stole some ideas from other people's rigs... total cost $50 plus $20 for a rivet gun I didn't own.

I decided to use my desktop MB / CPU / Memory and upgrade my main system with something new, so what is pictured in this rig is a:

Asus Maximus IV Extreme (has 12v GPU power on MB)
Sandybridge i7 processor
16GB Ram
Watercooled CPU

All of that is overkill, but I just pulled it from my desktop so meh...

Of interesting note, I had to use 16x to 16x risers on 2 of the slots or Windows wouldn't recognize the cards, I don't know why, but it is what it is.  1x to 16x risers on the other 3.

2 PSU's... 1 1200W and 1 1000W

And of course 5x Sapphire Toxic R9 280x  Main Specs:  TC=8193, MEM=1800, Engine=1100

As for length of time, I ran for 5 hours no problems with zero HW errors, I rebooted to remove killawatt voltage meter and post pics.

Unfortunately this speed does come with a price, the cards have to run at 1.256V  I can run at 765Kh/s per card at 1.2V if I lower mem to 1500 and engine to 1100.  This also lowers temps from high 70's to low 70's.

There are my secrets guys... took me weeks to tune these boys, but Toxics are best IMHO... now watch them go out of stock again.