Hi there

Quadro RTX 4000 should be comparable to RTX 2080, where Quadro will be better or is better is in viewport performance or in other apps like is 3DS Max, Maya or Cinema4D

Regarding the running multiple GPUs, I'm using RTX 2080Ti with GTX1080Ti and two GTX1080(in total 4 GPUs) all GPUs are OC as well

Performance is mixed for sure, single RTX 2080Ti is fast as two GTX1080's, GTX1080Ti with RTX 2080Ti and two GTX1080's rendering is quite fast...

Normally render with RTX 2080Ti and GTX1080Ti takes 7 minutes at 45 samples, with all 4 GPUs(RTX 2080Ti, GTX1080Ti, GTX1080 and GTX1080) rendering takes 5 minutes and 25 seconds at 45 samples and 3 GPUs(GTX1080Ti with 2113MHz OC, GTX1080 with 2164MHz and GTX1080 with 2113MHz OC) render takes 8 minutes or so

Personally I uninstalled 11.3 and went with previous version of Poser 11.2 I think because I didn't see big difference in rendering with RTX 2080Ti and mainly some issues with RTX 2080Ti rendering and Poser as well

@ghostship2 Try different driver, I use 442.01 driver on my build and no issues, tried Studio drivers which are rubbish, tried newer drivers which literally causing only problems like BSOD, TDR etc and due this I don't update drivers a lot, for GTX1080 and earlier 388.43 or 399.24 are great drivers for rendering if you running GTX1080 or earlier GPUs

If you are using multiple GPUs like RTX 2060 or 2070 with GTX1080 or earlier GPU then 442.01 or 441.41 are great drivers, newer drivers or Studio drivers are really bad for myself and my build

If I want to render with RTX 2080Ti then usually I render in Blender 2.8 and E-Cycles as this render engine is faster than Cycles

Hope this helps

Thanks, Jura