Sadly it is difficult to get more than 1 GPU working at a time, especially in Windows.. The case is rather large so not likely a thermal issue.
More eGPU news coming.
Well that's a shame. I was looking forward (as much as possible) to an external enclosure with 4 980Tis. A (real) Mac Pro tower that could support this internally would be ideal. It's looking like a hot rodded cMP, or a nMP with a single external GPU for me. Dell, Lenovo, or HP boxes for the heavy lifting.
Rominator, Netkas, etc. always enjoy reading about your accomplishments - keep up the good work!
I'm sincerely hoping the eGPU news is that you're launching a turnkey thunderbolt chassis & power supply solution; plug in your own video card and go to town.