ya know, you were heaping praise on your 960 4gb multiple times saying you can hit ~60 fps on high to ultra settings for most games. now you're settling for medium? for shame mysterd, for shame...
DOOM (2016) certainly isn't most games.
DOOM (2016) isn't on the best optimized engine, which pretty much is Id Tech for you since Id Tech 4:
Also, most games ain't eating up 2500-2600 GB of VRAM consistently on Medium, either. Thank God for having 4GB of VRAM here. This kind of VRAM eating, I usually see on High or UItra for most games here.
I'm going to mess with this and see how far I can push this game now.