I'll start by saying this project isn't for most folks but for those with a multi-monitor setup that want more powerful graphics it may be an option for you. Also, I'll add in, I don't really want a regular PC, don't want being the key words, and if I can get more performance out of my iMac then that's what I am going to do. I am aware there are more inexpensive ways of going about getting higher performance with certain parts but I am fortunate enough to be able to do this project and I am happy with the results. Ok, on to the meat n' potatoes of the project. My computer setup for the past few years has been a 27" iMac with 2 external 27" 1080p monitors. While this seemed to have worked for a while, I come to realize 3 - 27" monitors was a boatload of screen real-estate... resolution wise and physically on my desk. Which got me to thinking and researching. What if I cut down to 2 - 27" screens but beef up my video card if that's even possible or an option. I do a fair amount of video processing and would love the added benefit of real GPU processing power. I had already ordered: late 2015 5k iMac i7 6700k CPU R9 395X GPU w/ 4GB RAM 32GB 2133MHz Kingston Hyper X RAM 512GB SSD then the researching of eGPU's started, which lead to ordering: Akitio Thunder 2 box EVGA GTX 980 Ti SC+ ACX2.0 w/ BP GPU Corsair CX750M PSU and a few extra pieces to complete the project 2.5mm x 5mm Barrel Plug 2 - 4pin female Molex connectors paperclip The result: So the reasoning I give that this project is better for those with multi-monitor setups is that the eGPU doesn't seem to be powering the internal iMac screen, I can't be sure but performance on it seems a tad sluggish. Not sluggish like a slide-show presentation but just slower than when the eGPU is not connected. Normal video watching like YouTube full screen or Netflix and Hulu seem fine and I have yet to actually check performance on the iMac screen, it just "feels" slower. It is also now locked at no higher than 4k resolution only when the eGPU is outputting to the 2nd monitor. If I disable video output from the eGPU the iMac goes back to 5k and I can still utilize the eGPU processing power for rendering projects. However, eGPU performance on the external monitor is quite, quite good. The only game I have installed in OS X currently is Warcraft. On the 1080p monitor, Ultra Settings and every option set to the highest available setting I was getting on average of 99fps. I have not done thorough testing of any sort yet other than a few benchmarking programs and Warcraft so these are the results as of now. In Windows 10 I got to run 3dMark but as of yet I had to leave before getting done with FireStrike so I will post those results later. 3D Mark 11 =http://www.3dmark.com/3dm11/10969734 GPU Score of 19,343 3D Mark Vantage =http://www.3dmark.com/3dmv/5417862 GPU Score of 53,759 3D Mark 13/FireStrike = to be continued I will try and do more testing within Windows and OS X with results from both cards to show the difference the eGPU makes. I also do a little bit of Folding@Home for our Macrumors Team. And with the eGPU I was able to get my production up quite a bit. Now this I had to do from within Windows because for whatever reason F@H doesn't utilize GPU's on the Mac Client that I'm aware of. In just under 2 weeks I went from rank 249 to 60 or 360,000 points to 4.4 million points. There were days when I needed to work in OS X so I had to shut folding down but overall I am happy with how well the eGPU is working. For those interested in folding this may be something to look at. If anyone is interested or wants to see anything in particular in regards to pictures/specific benchmarks/etc please post below and I will do my best to get the results posted ASAP.