g-sync needed for 4k if gpu's constantly get 60+ hz?

[shmoo]

I'm going to be building a new system in the near future with the goal of 4k gaming among other things, and I've been reading about g-sync, which wasn't really around much when I built my last system.

I'm looking at two monitors at the moment:

Acer 32" Display Monitor 4K UHD 6ms B326HK
Acer 32" Display Monitor 4K UHD 4ms XB321HK (predator w/g-sync)

Both of these are 60hz monitors. From what I understand, g-sync will be nice to have if I'm not getting 60hz from my GPU's because I can dip below 60hz and my display will dynamically change the framerate while staying in sync with my gpu's and thus not be forced to 30hz (vsync) or tearing (seems to happen if you don't have g/v/free-sync).

Now if I have a rig with 2 1080's in sli, or I wait for a 2080 (supposed to come out in June?), or really I just run any set of GPU's that can keep up with 60hz in 4k with good settings, can't I just use v-sync and keep it pegged at 60hz because my gpu's should be able to keep up? I'm not trying to go over 60btw, I don't think I can tell much of a difference.

 

[krells]

If you can maintain 60 fps with a single GPU and either don't mind the extra lag vsync introduces or can deal with screen tearing it would be okay. If you are using a multi GPU setup to maintain 60 fps you will have issues with games that don't support more than one GPU. I would go with the fastest single card and the g sync display.