So I finally got my first gaming session on the new setup last night and so far I am very pleased. I think I landed at a good spot with my overclock @ 1500mhz core/8200mhz memory. I was able to go higher on both core and memory individually, but combined that is where I've landed. I think the card is hitting the power limit when I'm pushing both, so I think that is restricting getting the maximum out of each. I think I can get more with a custom BIOS but I am okay with what I've got.
Anyway, I played Fallout 4 for a few hours last night on a few different visual settings. The most demanding scenes I have seen so far are when I am outdoors with fog/thunderstorms, lots of foliage/objects, overlooking long distances during the day time. Lots of God Ray action going on during this time. There is just a ton of stuff going on with the lighting, the special effects, the shadows, the number of objects being rendered.
I first tested with visual effects turned on to Ultra/Max and with TAA enabled. This is a step above the 'Ultra' preset as God Rays increased from High to Ultra. In that demanding scene FPS dropped into the low 30s. Changing God Rays from Ultra to High, FPS jumps up by about 10. Disabling TAA gives you about another 5. So the minimum FPS range in that demanding scene was anywhere between 30-45fps depending on your settings. The game was very playable at all setups above for me though I did appreciate the smoothness from the higher rates.
The visual impact of changing God Rays from Ultra to High was about nothing. I still see the beams of light flowing through the objects from the light source and the game looks the same to me.
Nvidia has an interesting comparison page up where you can see the same scene with God Rays from Ultra to Medium. No difference. The performance penalty wasn't worth it and I won't be using Ultra.
TAA's impact was a bit noticeable even with 4k resolution. It kind of 'smooths' out objects/people into the scene. With TAA disabled, objects do stick out a little more as their edges aren't blurred but it still looks good. I am a little unsure if I'll use TAA or not.
4K in general was very nice. The jagged edges of 1080p are gone. Without AA you can still see the edges of objects with a very high contrast to one another but this is only visible when pixel peeping or staring hard and not easy to see during regular gameplay. TAA removed it completely and edges were hard to see even pixel peeping up close.
If you are OK with 40-60 FPS and don't mind an occasional dip into the 30s, gaming at 4k is very possible. If 40s are your minimum, you might have to disable some unnecessary special effects such as God Rays or Hairworks. Not a big deal since their benefit is so minor IMO.
If you want minimum 60fps @ 4k with max settings that is tough and I don't think we are ready for that yet, just way too many pixels to push around. You can probably get there by dropping some more important visual settings but I would rather drop the resolution at that point. If you're looking to max out your 144hz monitor and have a locked 120+ fps, you probably won't be looking at 4k for a while as that is even taxing on 1440p.
I know this was tested only using one game and despite it not looking very good, it is quite demanding. There will be a few tougher games and you may have to make more concessions around special/visual effects for them, but overall my experience in trying 4k has been a positive one.
I know this was a super long post, so if ya stuck with it, thank you. I know this was tested only using one game and despite it not looking very good, it is quite demanding. There will be a few tougher games and you may have to make more concessions around special effects for them, but overall I think 4k gaming is very reasonable.