I own a MBPr Mid 2012 with the following specs:
i7 3820QM @ 2.7ghz
Windows 10 technical preview
My egpu setup is:
Sapphire HD7970 6GB Overclocked Vapor-X edition (2x 8pin power)
500watt psu - 18/01 swapped to 1200watt silverstone psu to fix stability problems
Sonnet Echo express pro
Powered 1x to 16x molex riser - 17/01 removed due to instability - 18/01 added again because stability issues were due to $20aud psu
My setup if finally working!
Ran bootcamp driver installation.
Ran setup 1.2 (Thanks Nando!)
Ran test chainloader config
Booted with egpu recognised as HD7900 series in device manager.
Unigine Heaven 4.0 extreme preset:
Score of 947 windowed mode. Max fps 75 min fps 17
OpenGL score of 77
Not a real benchmark but fps didnt drop below 60 during the 1 hr of gameplay on max settings
On ultra settings the game is playable not dipping below 35fps with vsync on. Very high settings see an increase to a min of 45 fps.
Pretty surreal what can be done with a talented programmer (Nando) and a bit of persistence.