@mr_phoenyxx

The 1080 Ti should be faster than the 1050 Ti. I saw some posts from a couple of years ago with people complaining about slowness in Cycles with the 1080 Ti. Unfortunately, they don't mention a fix.

I'm not seeing any slowness from 11.2 update. But, I'm running a regular 1080 on Windows 7 with older drivers. I only update when absolutely have to update.

As for the 100 Pixel samples, Superfly is noisy especially for indoor scenes. To get a clean image, you have to crank up the samples or use a denoiser.