I have a 144 Hz monitor which supports G-sync but I do not currently have a dp cable. Does G-Sync play games like fortnite at all?
First: on hdmi funktionerit gsync not - so you need necessarily display port. General, I would recommend you to use DP and not HDMI or similar.
What does it worth? You have a slightly higher input lag than without sync but much lower than with V-sync. So if you play with Vsync - worth it anyway - you play without vsync and the tearing bothers you - it's worth it too. Do you play without Vsync and have no problem with tearing - it actually does nothing except increase your inputlag minimal (probably untouchable for you). If you get more than 144fps in fortnite, you would also trim your fps.
Since fornite is a Competetives game I would do without any Sync in favor of the lower input lag - only exception: Tearing distracts you so much that the use of Gsync improves your experience.
Personally, I've configured Gsync so that it's on at 30-144fps and off at 145fps. So I have no tearing problem with a few frames and no input lag problem with many frames.
