Thanks for the fast replies.

But at least i know now that its a cpu related thing, and probably nothing wrong with the gpu. Seems the cpu cant load the gpu or so, for this benchmark. Other silly benchmarks like furmark i can heat it up to full load. Before i was also afraid its a pcie issue, related to the cpu. Also in the ws790 bios i cant find any pcie speed setting, But as long as it works its ok.
So i guess all these weird results are normal (not ES related). But yes very very strange. Expecially the gigantic difference in on OC or stock. Maybe its really a benchmark issue. Did some weird run disabling half the cores, enabling 3.7Ghz but still low results.That seems about right - the 3495x is a similar die configuration and posts very bad Time Spy scores:
...
I wonder what's going on, the 3475X is XCC as well but scores almost double...except when stock, where it apparently performs like a Core i3?!

But at least i know now that its a cpu related thing, and probably nothing wrong with the gpu. Seems the cpu cant load the gpu or so, for this benchmark. Other silly benchmarks like furmark i can heat it up to full load. Before i was also afraid its a pcie issue, related to the cpu. Also in the ws790 bios i cant find any pcie speed setting, But as long as it works its ok.