Hi! I use a PE4C V2.1 with EC100 adapter. My laptop is a HP Elitebook 8470p with Intel HD4000, and I want to use a AMD Radeon 280X graphic card. I solved the error 12 with DSDT override and Setup 1.30 with Win 8.1. My problem, that the eGPU solution isn't stable. Sometimes it works, sometimes not. Yesterday it worked perfectly, I played a game, and I doesn't have any problem, but today morning, it booted to black screen, then I tried to activate after booting, black screen again. I tried a couple of times and later it generated white or red vertical stripes on my external display, so at the end, this morning I can not use my eGPU system, and I had to go to work. Any idea what causes this, or how I can overcome this problem?