diegovb

@Tech Inferno Fan Life and technical difficulties have gotten in the way of this, but I should be able to run the benchmarks somewhere next week assuming my computer cooperates with me (it hasn't lately).

Make sure to have installed the Boot Camp drivers so that the Thunderbolt interface works. Also, I turn on the GPU ~3-4 seconds before powering up the MBP; it's the only way I have gotten it to show up. FYI, for me, the graphics card showed up as an unknown device under the display adapters section until I installed the nVidia drivers with the GPU connected.

I don't have access to one until ~3 weeks from now, but I'll post them then

I am pretty certain that those results are from the 1070 and 3D Mark is just incorrectly reporting the GPU name. Regardless of that, Optimus IS working for me with the 1070 for me. I am sure of this since I get better performance, and I disabled the 750m on the device manager. However, I have been having performance problems on certain games, on some more than others, so I am going to wait until I have access to an external monitor to use the setup again. Kind of disappointing, but what can you do.

Cool, I'll def. try that next time. Games on the internal monitor get a performance hit as well. Try setting Windows to output only through your external monitor, making sure that the external monitor is connected directly to the graphics card (and maybe you need to disable the 750m? i don't remember exactly). Here's the results for the 1070 running through nVidia Optimus on the internal display: http://www.3dmark.com/3dm11/11379920

I have not, but I assume it won't help with anything since the enclosure runs at PCI-e 2.0 x4 which has less bandwidth than a Thunderbolt 2 connection. Nice tip! Thanks! Yeah, I'm getting the same booting issue, takes 1-5 tries to actually boot up.

Sure! I didn't come up with this for the record. I'd like to give credit to the OPs but I can't really; I got info from a bunch of sources while browsing many threads so I don't remember which pieces came from where. Basically, Optimus won't kick in unless it sees an Intel integrated graphics card and an nVidia card. You also want this nVidia card to be your eGPU, not your dGPU. For all of this to happen you need to: Install rEFInd, a third-party EFI bootloader for your Macbook. Warning: this is risky because you're messing with boot-level stuff. You should be fine, but if this makes you scared go research about it. http://www.rodsbooks.com/refind/ Once you're booting through rEFInd, modify the refind.conf file to enable the Intel Iris Pro card on your Windows partition. You need to change the spoof_osx_version flag. More info here: http://www.rodsbooks.com/refind/configfile.html For the record, rEFInd can be circumvented if you hold down ALT while booting; it might help you fix stuff if you screw up and Windows isn't booting. If you got this far, you should be able to go on Windows, open Device Manager, and see 2 graphics adapters, your GT750M and some generic named one. Now you need to go on the Intel website, install their graphics drivers, and restart your computer. Now the 2 graphics adapters should show up with their correct names. Download gpu-switch and use it to set your integrated card as the primary one (on the Windows side, IDK if doing it on the OS X side helps or not). I don't know why, I think that this way Optimus knows to route your dGPU/eGPU stuff to the display through the Intel chip or something. Download from here: https://github.com/0xbb/gpu-switch Restart, and now Optimus should be enabled on your iGPU/dGPU pair. Take note that, at least for me, one of the drivers was super buggy and maxing out one of my CPU cores (by spamming interrupt signals, if you're curious). I fix it by disabling and then re-enabling the Intel Iris Pro on the Device Manager after every boot (I know, pretty annoying). If you let it max out your CPU cores it will mess with your framerates in some games. Almost there. Disable your dGPU, and then restart with you eGPU connected. Now you should be able to play dem mad gaemzzz!!11!1! If your games are CPU-bound, open Resource Manager and make sure your CPU isn't being artificially capped (the blue bar in the graphs, you want it to be ~100%). Good luck! Please post here if it works, because my process was not in the same order since I was trying multiple things that failed before I actually got it to work.

There were some complications outside normal for getting it to work on my internal screen. Running games on a screen connected to the graphics card directly was pretty much plug and play. For getting it to drive the internal screen I had to instal rEFInd to enable the Intel graphics chip on Windows, then install the Intel graphics drivers, run gpu-switch to select the integrated chip as primary, disable the GT750M on the Device Manage, and restart. It still take a few tries to boot up, but once Windows loads and the video card shows up in your Device Manager you're good to go! As far as the bandwidth thing, my assumption was that GTA needs to send more texture and vertex information to the graphics card or something. Just a guess though.

It's been hit and miss. I can hit 1080p60 on Mirror's Edge Catalyst. Rocket League can hit 60 FPS at 2880x1800, but not consistently. GTA V runs at like 40 FPS on 1080p, but neither the CPU nor the GPU is the bottleneck, so I'm assuming it has something to do with the bandwidth of the Thunderbolt interface.

Not yet. Any particular one you're interested in?

It is done! I got my GTX1070 to work on my Mid 2014 Macbook Pro 15" using Windows 10. I managed to get Optimus running, which means it can power my internal display! Nitty-gritty below! Software deetz: Windows 10 installed via Bootcamp Intel Iris Pro drivers v15.40.22.64.4424 nVidia Graphics Drivers v383.39 rEFInd bootloader (to enable Iris Pro on Windows) gpu-switch by 0xbb (to set Iris Pro as the display's main driver) Hardware deetz: Macbook Pro 15" (Mid 2014), 2.5GHz, Iris Pro + GT 750M AiKiTiO Thunder2 (powered by its power brick) MSI GeForce GTX 1070 Founders Edition Corsair RM550x (to power the card) Some very elegant black electrical tape If there's anyone interested in any part of the process (or anything else) leave a comment and I will update the post!