P-Mac

Because you're extending a very sensitive, high-throughput interconnect many times its designed length via an unshielded, non-active cable that's likely of subpar quality, and splicing in power on top of that. The GPU and the CPU are literally the two busiest, most powerful compute devices in the system, janking up the interconnect between the two is just asking for trouble. All it takes is one bit to get flipped wrong and the GPU driver crashes, and OS X is far less forgiving than Windows when it comes to GPU crashes. To me, using a PCIe riser is like trying to type 150wpm using nothing but a few strands of balsa wood glued to each finger. It might work, but the chance of it failing is far greater. (And yes, the Thunderbolt cable is transferring all of that data as well. But it's shielded, and there's circuitry on either end to amplify and clean the signal, neither of which a PCIe riser has.) I honestly don't think I've seen anyone do a build that used a riser and stuck with it, they all ended up realizing risers are crap* and switched to powering the Thunder2 directly (as the box expects to be powered). * = except for that one guy that used a solid riser that was basically the length of the PCI slot itself, and it didn't add power, he just needed it to clear something in the case he was working with. You literally only need a pair of scissors and a bit of bravery to wire the Thunder2's barrel connector to the PSU. Cut the connector off the Thunder2's PSU that comes with the box, strip it carefully (because it's a coaxial cable, not two adjacent wires), twist the outer negative strands together to form a "wire", strip the inner positive wire. Then you strip the CPU 12v plug from the ATX PSU, and twist them together. You don't HAVE to get a fancy barrel connector, but it's technically the "right" way to do it. I was impatient. I ran my build like that for a week until I got around to actually soldering the connections, and it rendered video and played games flawlessly, even while running at 125% TDP in Windows.

Copied from my build thread (MacBookPro11,3 / 750m / Thunder2 + GTX 980) My full boot/setup process for mobile gaming via Optimus, coming from normal eGPU usage with external monitor is as follows: Leave eGPU unplugged Boot into Windows Disable the 750m in Device Manager (I usually leave it enabled when booting Windows normally) Run the switch-GPU script to set the iGPU as primary Shut down Windows Plug in eGPU and start the computer Select apple_set_os (I've renamed this to "iGPU Enabler", the far right icon in rEFInd) Boot Windows You'll need to install the rEFInd boot manager, the apple_set_os EFI app, and the switch-gpu Windows utility. To "get out of Optimus mode", you need to run gpu-switch to set the dGPU as primary, re-enable the dGPU in Device Manager, and then reboot without running apple_set_os first. Keep in mind that there's a bug with the Intel drivers in Windows 10, and once you've got Optimus up and running, you have to hibernate the system and then power it back on again (without unplugging anything) to get the driver to stop burning 10% CPU constantly. After that, it's ready to go.

@goalque You're more than welcome to use my setup for beta testing as well. I have a MacBookPro11,3 (750m), a Thunder2, and a reference model GTX 980 that I believe is EFI compatible. (GPU-Z in Windows has the UEFI check mark checked next to the VBIOS) I've extracted the BIOS if you'd like me to send it over or anything. Currently, when I run the EFI app, it says "eGPU Not Detected" and only lists the 750m and the Iris Pro. I have Optimus running the "manual" way in Windows, via apple_set_os and rEFInd, so I can confirm it works, but automation would be nice as well.

Found a fix for the Windows BSOD upon driver initialization during the boot process, added it into the main post. "I figured it out, a trip to Device Manager and I noticed there was a "show hidden items" menu option. Clicking that revealed that I had two GTX 980 devices that weren't connected for some reason, and the driver was fighting itself upon initialization during boot. Rebooted into Safe Mode and ran DDU to clean out the NVIDIA driver, reinstalled it in normal mode with the eGPU connected, and all is well. One GT 750m, and one GTX 980 in Device Manager when viewing hidden devices. If you're having driver issues like I did, you might want to check this."

If you've enabled "Use High-Performance NVIDIA Processor" in the NVIDIA Control Panel, but the apps are still using the iGPU, then I've got no idea. Sometimes apps do that (I had issues when running VR apps without a monitor attached to the eGPU). Wish I could help...

Try disabling "Displays have separate spaces" in Mission Control, System Preferences. I was having a stutter every single second until I disabled that option, now I can run multiple monitors (including the internal display) without issue.

Nope, just be sure to terminate them individually, I went with both shrinkwrap and gaff tape just to be double sure, there's tons of mixed polarity in the ATX 20-pin connector and the last thing you want is two things shorting out. Electrically, the wires being cut and the wires not being connected to anything are the same, so the PSU "sees" nothing different. If it works with those wires not plugged into anything, it'll work if those wires are trimmed down.

This isn't even my final form! "DotPusher III" Hardware: Mid-2014 MacBook Pro (15-inch) Core i7-4980HQ (2.8 GHz) NVIDIA GT 750m NVIDIA TITAN Xp 12GB (GP102-450) (previously 980, 980 Ti) Also tested with: EVGA GTX 1080 SC (see bottom of post) Akitio Thunder2 Corsair 550w ATX PSU "Fat .50" Ammo Can (800 rd 5.56mm) Software: Windows 10 Latest macOS version automate-eGPU.sh rEFInd Boot Manager apple_set_os EFI application Tools: Screwdrivers Channel-lock Pliers (or vise grips) Jigsaw / Dremel / Angle Grinder / Metal File / Sandpaper The Build Honestly, the build was surprisingly simple! Popped open the Akitio, used channel-lock pliers to pry the front side of the Akitio open to allow for the length of the GPU. Added gaff tape over all of the metal parts, just in case the card came into contact with the bare metal of the bent Akitio enclosure. Got the card handy, a gorgeous little reference model GeForce GTX 980. On a side note, I actually had an MSI GTX 980 GAMING 4G but ended up trading it for this reference unit, as it was one of the ugliest pieces of hardware I've ever seen, and the reference models are just beautiful. (Form over function, but isn't that the Apple way? :P) The card slotted right in, no problems here. Next up was the power supply. I used a Corsair 550w unit, but cut everything besides the two PCIe power connectors and the CPU 12v rail (to power the Akitio). Terminated all the ends with shrink wrap and gaff tape on top of that, and taped all the unused lines down to the side of the PSU. It was also during this step where I hotwired the PSU to always be "on" via the paperclip trick...except I just traced those wires back to where I was going to make my cut, and soldered them together. For the Akitio's power, I used the molex-to-barrel-adapter guide, but instead of being patient and getting a proper barrel connector with two leads, I cut the barrel connector off of the Akitio's power supply that came in the box. I like to live life in the moment, I guess...but the fruits of my labor were revealed when I stripped the wire and it turned out to be coaxial instead of side-by-side! No matter, I said to myself, as I twisted the outer fibers into a solderable piece of wire, and stripped the inner wire as well. Verified polarity via a multimeter, and soldered the Akitio barrel connector to the CPU12v line from the PSU. A bit of shrink-wrap and gaff tape later, and I had a nice little feed for the Akitio coming off of the PSU. No powered riser bs, no extra Akitio power supply. Clean and simple. PCIe plugs went straight into the GPU, I gave em a little bend so they'd hug the edge of the magazine holder. I also re-routed the front LED from the Akitio's box around the back of the PCB to where the Akitio power plug is, so that that area of the magazine holder lights up blue when the card is active. At this point, I took the magazine holder and made cutouts for the GPU ports, ventilation, and PSU ventilation. Covered the rough edges with gaff tape so they wouldn't fray and get sucked into a fan (plus it looks a bit less janky). The Akitio with GPU slid perfectly into one side of the magazine holder (make your measurements first before going shopping!), but was sitting too low for my cutout to be centered on the GPU's cooler...nothing a little packing foam (from the Akitio box!) couldn't fix. The PSU slid in with...some effort. From my measurements, I knew the PSU wasn't necessarily going to fit, but it was close enough that with a bunch of gaff tape to keep the bottom and sides secure, it doesn't move anywhere and there are no signs of any danger of it falling out after a good 2 weeks with the setup. I just try to keep this side hidden, it's pretty garish. EDIT 070416 (MURICA DAY) Added green underlighting because #AMDsux #teamNVIDIA (lol). Here she is at work (literally, at my work), powering 2x 120 Hz displays & a bunch of OpenCL compute. The Experience It was time to start her up. Plugged in PSU, switched it on, plugged my 4K 60Hz monitor into the eGPU, plugged the TB cable into the Mac and hit the power button. Fired right up, booted into Windows and re-installed the NVIDIA drivers. After a reboot, the card was recognized, and I was playing Doom (2016) at ultra quality 1440p inside of 10 minutes. Not too shabby! I spent some time in MSI Afterburner, customizing a fan curve to keep it pretty quiet during moderately high gaming workloads, but ramp the fans up quickly if the temperature went north of 70º C. Boy, this thing is loud when the fans are at full tilt, but I'm glad they; the reference cooler is no slouch, and with fans cranked to max it's actually able to pull down the temperature from 80 down to 70 while furmarking! With a bit of tinkering, I settled on a final, furmark-for-8-hours-stable overclock of +225 MHz core, and 7400 MHz on the memory. Using ThrottleStop, I also undervolted the i7 in the laptop, and downclocked it to ~2.4 GHz. Windows runs a bit hotter than OS X, figured I'd help out as much as I could. I gotta say, it feels good to put down an 80th-percentile score in 3Dmark Fire Strike with a MacBook Pro. On the OS X side of things, automate-eGPU.sh took care of everything without a hitch. I did notice some weird stuttering every second (and exactly on every second), but with some tinkering I found out that the "Displays have separate spaces" option was the cause of the issue. Disabling it made OS X run perfectly smoothly afterwards. Final Cut Pro X immediately took advantage of the new GPU, and I was able to play back Sony FS5/A7s 4K footage with a few layers of colorgrading on it much smoother than with the 750m. It can almost handle playing it back at full-res, which was just astonishing to me. Analyzation of footage for stabilization just rips, along with optical flow retiming. Adobe CC was able to take advantage of the card as well, Mercury Playback Engine (CUDA) felt much smoother than on the 750m, though I haven't been using Premiere in a while so I didn't do much testing in CC. Unfortunately, After Effects is not really accelerated by the card, but oh well. To get Optimus to work with a 750m-equipped MacBook Pro, I turned to this reddit thread detailing the installation of rEFInd and using an EFI utility called apple_set_os to get the Mac to expose the Iris Pro when booted into Windows. I also customized the rEFInd interface because the default skin looked like something out of Mac OS 7.5.3 (I half expected little puzzle piece extension icons to start loading across the bottom). The reasoning for using apple_set_os instead of the built-in spoofing feature in rEFInd is because I'd like to normally run Windows without the iGPU enabled, but retain the ability to switch into "Optimus mode" when I'm mobile. My full boot/setup process for mobile gaming via Optimus, coming from normal eGPU usage with external monitor is as follows: Leave eGPU unplugged Boot into Windows Disable the 750m in Device Manager (I usually leave it enabled when booting Windows normally) Run the switch-GPU script to set the iGPU as primary Shut down Windows Plug in eGPU and start the computer Select apple_set_os (I've renamed this to "iGPU Enabler", the far right icon in rEFInd) Boot Windows If all goes well, I'm in Windows with the GTX 980 as the Optimus "high-performance NVIDIA processor". Game performance takes a bit of a hit, but not anything significant...I can still play most titles at 1080p ultra quality, and they look great on the MacBook Pro's retina IPS display. Lingering Issues Thankfully, all of the lingering issues I have only involve the boot process. Sometimes the entire system refuses to POST (sits at a black screen without ever chiming), and I have to hold the power button for a few seconds and try again. When it does POST though, the next hurdle is whether the driver (in OS X or Windows) will initialize properly. Sometimes it doesn't want to play nice, and I'll get a BSOD on booting Windows with DRIVER_IRQL_LESS_OR_NOT_EQUAL, but a restart or two will do the trick. FIX FOR BSOD ON BOOT: I figured it out, a trip to Device Manager and I noticed there was a "show hidden items" menu option. Clicking that revealed that I had two GTX 980 devices that weren't connected for some reason, and the driver was fighting itself upon initialization during boot. Rebooted into Safe Mode and ran DDU to clean out the NVIDIA driver, reinstalled it in normal mode with the eGPU connected, and all is well. One GT 750m, and one GTX 980 in Device Manager when viewing hidden devices. If you're having driver issues like I did, you might want to check this. (NEW) FIX FOR macOS NOT BOOTING: Run Goalque's script in "-a mode". This alters something regarding the thunderbolt chipset on every shutdown, so when rebooting back into macOS, the eGPU will initialize properly every time. For OS X, I just get a black screen with my monitor showing no signal input. Again, a restart or two fixes this. (Honestly, I've had the NVIDIA Web Driver do this with the internal 750m, so it's just a normal driver-crashing-on-init issue, not specific to the eGPU.) But once the system is booted, it is rock solid, and I've never had anything crash or fail (besides overclock-induced crashing in Windows, but that's my own fault). It all seems to be based on luck of the draw, as I'll have some days where it'll work flawlessly and I'll be bouncing between the two OS's with no problem, other days I'll get 8 failed starts in a row. If anyone has any idea how to help mitigate these failed starts, I'm all ears. The only other issue I can think of is lack of display brightness control when running in Optimus mode (anyone got any clues?), but it just means I have to set the brightness from within OS X first before going through the boot process. Final Thoughts It was totally worth it. I'm in love with this setup, it truly feels like the best of both worlds. The i7-4980HQ in the MBP is no slouch of a CPU, the only thing my setup was missing was some graphics horsepower, and the GTX 980 more than comfortably steps up to the plate. My work experience has had amazing fluidity, and gaming has gone from sub-720p resolutions on the latest titles to gorgeous looking, maxed quality 1080p and higher. Less demanding titles (CSGO, Borderlands Pre-Sequel) even run at 4K 60fps, which is a sight to behold. The Oculus Rift that I got my hands on runs perfectly smooth, with no VR-sickness to speak of. And all this, in a "portable" setup. I now have 3 levels of portability (with associated levels of performance): full desktop mode, Optimus (so I don't have to lug a monitor around to LAN parties or remote editing / rendering of CGI), and of course the laptop by itself (which, with its Core i7, is still no slouch, at least when it comes to CPU compute power). It's also extended the longevity of my machine a lot, since I was looking at the 2015 and purported 2016 models for their GPU upgrades...but not anymore! The only thing I'm looking at is the moment NVIDIA releases Pascal drivers for OS X...and my poor wallet might have to take the brunt of a GTX 1080. The Future I'm still on the hunt for a better case, but all of the computer cases I've found are...well, computer cases, and far larger than this magazine file setup. So I'm looking at...different solutions. An old army surplus ammo box looks like my next case, and it has a handle at the top, which I can't live without after having this magazine file for a couple weeks. I'd love to pick up a modular SFX PSU so that the PSU actually fits into the magazine holder without any modification necessary, and if it's modular, it'll help keep the cables clean and tidy, with no drive and fan power cables to cut. Hope you guys enjoyed the adventure, and that some of the solutions to the little quirks I found help out someone! Happy eGPU-ing! --- EDIT 070416 (MURICA DAY) Just for kicks, slapped a buddy's GTX 1080 into the chassis to test with Windows. It required a driver reinstall as the system didn't detect the 1080, even after rebooting...it seems that the NVIDIA driver enumerates the cards in your system at install time and will only install the drivers it needs to, not all of them (different from the way OS X does it). The driver install worked fine without having to run DDU and cleanly install. YMMV though. The added compute power of the GTX 1080 was more than welcome to help mitigate the performance hit you take when using Optimus. Crysis 3 ran at the laptop's native resolution (2880x1800) at around 45-60fps with all settings cranked. Beautiful. I was really looking forward to testing out Rise of the Tomb Raider on it, but ironically there's a bug with Pascal cards and NVIDIA VXAO, so I couldn't get a fair comparison. Wish I could keep it, but the lack of Pascal drivers for OS X keeps me on the 980. For now. EDIT 071816 Acquired a "Fat .50" (actually an 800x 5.56mm) ammo box and made the primary cuts using a pneumatic angle grinder + cutoff wheel. Test fitted the Akitio and PSU. Currently need to drill the PSU & AKT mounting holes, but also trying to figure out what thread pitch the Akitio's mount holes are (anyone got a clue?). Specifically, the ones that the Akitio's own case's captive thumbscrews screw into. EDIT 072016 Finally finished the ammo can case after much measuring, cutting, and drilling. As the barrel plug was going to be flush against the side of the case, and I didn't want to have to loopback the cable like I did in the magazine file, I ended up soldering the CPU12v rail to the back of the Akitio's PCB. Pre-tinned the wires and plopped them onto the PCB, then secured it with gaffer's. Verified the correct solder points thanks to /u/Dippyskoodlez, who found the info from these very forums. Singed the PCB a bit, but oh well, close enough. EDIT 050517 NVIDIA released Pascal drivers for macOS. Upgraded eGPU to a TITAN Xp. Benchmarks available upon request. Yes, it's completely a ridiculous setup now—I was only able to upgrade due to external circumstances. Diminishing returns starts to creep in (even for the much-more-fairly priced 1080 Ti) due to the TB2 bottleneck.

You can also hibernate or sleep the computer and wake it back up and it'll fix the Intel drivers churning away at the CPU. (Works for me on Win10) On a side note, have you ever experienced the whole setup refusing to boot randomly? Like you won't even get to the startup chime...whenever this happens, I have to hold the power button until the computer turns off (I watch my USB drives and/or the eGPU's LEDs) and then try again to start up. It only boots with some luck, but once it boots it's rock solid... I'm only asking because I have the same exact Mac and was wondering if it was system dependent.

Hi all, thanks to your posts and knowledge, I was able to get an eGPU rig with a GTX 980 up and running with very few issues! It's been great so far. One of the lingering issues I've had is having to play the lottery whenever I start up the Mac...it seems like only one time out of 5 will the machine actually POST and play the startup chime and continue booting. Most other times, the GPU will initialize (I see the LEDs turn on and the fans spin up and return to idle), but the Mac just sits there at a black screen and never plays the startup chime. No amount of shuffling between thunderbolt ports (on both the Thunder2 and the laptop), or praying to the PC Master Race gods has seemed to have any effect on whether the machine will successfully boot or not. Sometimes it'll boot right on the first try, and do so 10 times in a row, other times I'll have to sit there and hold power to force-shutdown the machine and retry 6 or 7 times before it'll boot. Any ideas? Specs are as follows: 2014 MacBook Pro 15", i7-4980HQ, GT 750m Akitio Thunder2, MSI GTX 980 Gaming 4G, Corsair 650w PSU