Since Mavericks and Yosemite we can't use more than 2 nvidia gpis in MacPro. Any news in 10.10.2? Maybe someone found the solution?
Your assumption is incorrect. Even the old MacPros can support 3 double wide Nvidia GPUs. I hope to be testing a Titan Z in one of mine very soon.
Your lane width is X8 in slot 1?
Your assumption is incorrect. Even the old MacPros can support 3 double wide Nvidia GPUs such as GTX Titans, GTX 780 Tis and GTX 680s {you do have to remove HD bays 2-4 to fit 3 in there and you need sufficient auxiliary power}. I hope to be testing a Titan Z in one of mine very soon.
Great setup. Thanks for info. Which version of OSX are you using?
Right now (and in the relevant posts/pics, above) Mavericks, but I need to install Yosemite to run the Titan Z.