Keep hitting GPU threshold.

So when running certain hash-types, i'm frequently hitting "GPU threshold" of around 83c with my GTX 1080ti.


Also to note, it pretty much only happens when using Rules.

Build:
Case   - NZXT S340
GPU1  - GTX 1080
GPU2  - GTX 1080ti
PSU    - 750W

I suppose I could increase temp limit in afterburner or something, but surely this temp is a little too high?

Anything I can do to lower temps?

Update:
GPUs are not FE, GPUs are in Slot 1 + Slot 2 in my motherboard. Would seperating them in Slot 1 + Slot 3 make a difference?
My GTX 1080ti model - https://i.imgur.com/nV3O2Zi.png