Well, got my GT710. Got it to boot using nv_disable=1 and installed the web driver for 10.11.5. Now I got some problems trying to boot. Using only nvda_drv=1 was not enough and the machine rebooted during boot. The Sapphire Radeon HD 7950 Mac Edition is available from OWC and Amazon. The Radeon HD 5870 is available from OWC and Apple Store USA. The NVIDIA Quadro K5000 for Mac is available from OWC and Amazon. The NVIDIA Quadro 4000 for Mac is avaiable from OWC and Apple Store USA. APPLE MAC PRO 5.1 2x Six-Core CPU's Intel Westmere Xeon 2,93 GHz. (X5670) PNY NVIDIA Quadro 4000 for Mac graphics card. Video editing in Adobe Premiere Pro CC with Adobe Mercury Playback Engine hardware acceleration. Try upgrading to the latest driver for the video cardThe latest driver can be obtained from www.nvidia.com Note: Remember to uninstall all drivers and reboot your system prior to installing your new card. Change the refresh rate of your monitor to optimal. Or set it to Adapter Default, then Optimal, 75Hz, 80Hz, or 85Hz.

The drivers were made available on Wednesday, with the release by xlr8yourmac. Version 378.10.10.10.15.114 is specific to the current High Sierra build, and will need to be updated and re-released for every incremental upgrade of the operating system that follows.
Nvidia notes that the macOS Security & Privacy Preferences may open during the installation process, necessitating the user to allow the installation prior to completion. The driver contains unspecified performance improvements and bug fixes. Additionally, the driver package that includes a new CUDA download that includes the new 9.0 version of the toolkit, plus beta support for iMac and MacBook Pro systems with Nvidia graphics. Specific MacBook Pro and iMac models include those produced between 2012 and 2013 that are compatible with High Sierra. Brief testing of the new driver with an external GPU and Nvidia GeForce 980ti showed compatibility of the combo restored under the 10.13.0 beta release of High Sierra.
Further AppleInsider comparative testing on Nvidia versus AMD cards in Thunderbolt 3 enclosures will resume as a result of the release. The new Quadro and GeForce macOS Driver release is. The updated CUDA driver and supports macOS 10.12 Sierra and up.