sleepydragon

That is what it should be. The dGPU and iGPU wont work with EFI (it will give the internal screen a black screen). That's why the dGPU must not be an nVidia otherwise you won't be able to install the drivers (as it will mess with the dGPU card). Once you install the nVidia driver and plug in the eGPU and the external screen it will show everything on the external screen (with drivers installed). Also the sound card wont work. But if you use a TV then sound will work with HDMI output. Otherwise elgato thunderdock also has sound capability. Or you can pick up a cheap usb sound card. Many options really... As of today everything's still working perfectly and I'm loving my better-than-desktop setup. I rarely ever get bluescreen and I'm playing games at an unimaginable fps compared to the best rmbp you can get

Thanks for the guide. I have success with similar setup: Macbook Pro 17" early 2011 and Akito Thunderbolt + nVidia GT 970 (+PSU & whatnot) What's so interesting is that the system works with the daisy-chained elgato thunderdock which gives me a lot more ports to use it with. I tried with the DIY 1.2 which I got for my other rMBP early 2013, but I could not get it to work with the thunderdock (without the thunderdock it's fine). With the thunderdock the compaction keep hanging, I assume that it's because of all the extra stuffs that snug in there. Another thing noted with this system is that it may work without DIY 1.2 because nVidia card got recognized and worked without any error. However it's really on-and-off and having to replug the thunderbolt drives me crazy (BIOS really freaked out when it sees a graphic card attached to thunderbolt). With EFI boot, it works flawlessly 10 out of 10 times. I also used this guide By Popular Demand: My "Better Than Bootcamp" Guide to Installing Windows 8 : mac to help with installing Windows 8.1 EFI without the need for a second machine. If you install it from a clean disk it will not give you trouble with the error before finishing up (which I assume has something to do with it unable to modify the EFI partition created by MacOS). Then you can restore Mac as outlined by that guide. Also you won't need to create the new partition called Windows Boot as suggested by the guide, because after installing Windows 8.1 it will create a new recognized boot option called "EFI Boot" and it will work as well (save you 128MB of disk and some troubles of partitioning really). If you run into trouble partitioning the disk for MacOS, simply run an extra line when doing the diskpart in setup: create partition primary After creating the Windows partition as outlined in the guide. It will create a new partition with the rest of the empty space. Then you can format it using Disk Utility and install MacOS after done with the Windows Installs.