Most important ———————- Thanks a lot to Dschijn and sedor for their invaluable help as well as for goalque’s script without which I would have never been able to get my eGPU working! HARDWARE —————— As I was aiming for a cost-effective solution to add GPU-power to my Mac Pro, as well as being more flexible concerning graphics cards, I used inexpensive, already tried and tested parts. Mac Pro 6,1 (Late 2013), 6-Core, AMD FirePro D500 MacBook Pro Retina (Mid 2012), i7 2,6 GHz, HD4000 / GT650M AKiTiO Thunder2 Cooler Master Elite 130 PCI-Express x16 cable Delock PCIe-Riser card x16 bequiet! 530W PSU I mainly used the same setup as sedor SOFTWARE —————— Currently OS X 10.10.4, latest NVIDIA Web Driver (346.02.02f03), CUDA (7.0.64) and most important - the SCRIPT of goalque to get the eGPU automatically installed. Comments ————— The 4K LG 31MU97 (SST) works perfectly with 4K/HiDPI @ 60 Hz The UHD Dell UP3214Q (MST) does NOT (only 30 Hz) - as often with OS X (only reliable way to make it work with 60 Hz is using Windows/drivers) I’m also using this eGPU with my old 15“ MacBook Pro Retina (Mid 2012, HD4000 / GT650M) with only Thunderbolt 1 and almost the same benchmark scores. While playing (most of the times with 3840x2160) I experience „hiccups“ / dropouts (more so with the MacBook than the Mac Pro). As the eGPU can be used with my Adobe Apps (currently primarily Photoshop and Lightroom, in the future Premiere Pro, After Effects as well) it’s very useful with my work. Next steps ————— I will now start reading all the great information in this forum in order to solve some of the problems I still have - maybe I should have done this prior to the build up of my eGPU ;o)… By checking the information I will surely get a clue if it makes sense trying to get the eGPU working with my old >Gigabyte R9 280X OC< and the >FirePro W7000< (I already have been told that AMD graphics cards aren’t that easy to use).