Count'em, 4 yes FOUR Titan-Xps all running at once.
The Otoy Octane benchmark of 769 means they scored equivalent to nearly 8 @ GTX980s. (769% of 1 @ GTX980)
I don't believe anyone has posted such a score before.
On Blender I ran same test as Barefeats did here:
http://barefeats.com/imacpro_vs_pt4.htmlAnd the scores are not CPU bound at all. As in I can put a Titan-Xp in cMP or nMP or 2016 TB3 15" MBP and I always get 2:05. Barefeats got 127 seconds, which is of course nearly the same score.
Anyhow, with 4 Titan-Xps I got score down to 38 seconds. New iMac Pro needs more than 10x that much time. Two Titan Xps needed 65 seconds. 3 of them got it around 44.
Now the caveats, using all 4 TB3 ports means I can't have power connected, and the eGPU enclosures don't offer enough. So the MBP goes dead after awhile. And there is some jerkiness to motions on screen, especially the built in one. 13" with no dGPU is much smoother, but it only has 2 TB3 ports.
It took several boots to get all 4 to show up, frequently I only got 3. And with these cards so hard to get, I doubt I'll have 4 laying around again. 3 were on TB3 while final card used a TB2 case and Apple TB3/TB2 adapter.
Aside from the awesome numbers, I don't recall seeing 6 Total GPUs in System Profiler before.