I know it's not techincally 'approved', but still out in the wild (i.e. not at my base system), emergency system available to me is a bit older - anybody running Resolve 11 on a macpro 2008? This one is 2x 4 core, I can put nearly any GPU in it that'll fit as long as the tower itself is useable...
[John Tissavary]" anybody running Resolve 11 on a macpro 2008?"
Pretty iffy. I am finally giving up on my 3,1 8-core, basically because its the OS version that is letting me down. It was fine up to Mountain Lion, but that's as far as she goes. The reality is that you will need something later than a MacPro 4,1 if you want to take advantage of any of the faster, stronger nVidia cards unless they are flashed for Mac -- even then, some of the Mac-approved nVdia GPUs (even the Q4000) won't run in an earlier MacPro, so be very careful with choosing the peripherals.
"I always pass on free advice -- its never of any use to me" Oscar Wilde.
So far my experience is a bit different. I've got a spare 3,1 2x 4 core that I've been experimenting with a bit...
Have 10.9.5 running right now, no problems at all. Tried a few different GPUs but haven't settled just yet - I really want a GTX 9xx in here, but those don't work with Mavericks. But all the earlier-than-Maxwell GPUs I've tried have worked just fine so far.
Have a Yosemite boot drive on there with a brand new GTX 970, which besides the problem with CUDA and Yosemite, works beautifully. Hopefully Nvidia and Apple get that sorted quickly, because it could breathe new life into an older system.
No doubt the PCI bus is a bit of a bottleneck, but in terms of usability, GPU improvements are noticeable.