I am pretty sure that this is the card that is making the trouble here. HBM2 on it is like 12-14C hotter than the core, unlike any other cards I have where the difference is smaller ...

Any idea how to fight it? Its already undervolted, and fans are running quite high. Current room temp is around 18C, so can't really improve much on that front.

Would any additional fans do any good? Like case fans from both sides blowing into it or something?
Any other ideas?