Originally Posted by Notty
Not true. Vsync will always add input lag. Altho if you cap lower than refresh rate you wont hit its ceilling and input lag is lower, but still higher than vsync off.
Also with this driver based gsync we should cap around 10 fps lower than refresh rate because it is very imprecise and you are constantly hitting gsync ceilling, creating either tearing or input lag. The 3fps rule is only valid for gsync modules. Join us at blur busters for more info.
The difference between gsync + vsync and fps cap is 1ms compared to vsync off at 240hz. No one will notice that difference, but you'll definitely notice some screen tearing with vsync off and not only that but you have potential for microstutter at ridiculously high framerates as mentioned in the Gsync 101 writeup on blurbusters.
"So, for competitive players, V-SYNC OFF still reigns supreme in the input lag realm, especially if sustained framerates can exceed the refresh rate by 5x or more. However, while at higher refresh rates, visible tearing artifacts are all but eliminated at these ratios, it can instead manifest as microstutter, and thus, even at its best, V-SYNC OFF still can’t match the consistency of G-SYNC frame delivery."
It is also false that you need to cap your fps 10 below when using a freesync display with an nvidia graphics card. Battlenonsense has a video comparing input lag values with a 144hz monitor at 138 fps cap. (He let me know he likes to cap 6 below max refresh because some games aren't as consistent in keeping the frame limit cap so to be safe he does 6fps to avoid ever hitting the ceiling.) The monitors built in frame counter may be showing that you are hitting the ceiling constantly and jumping all over the place but at least with the VG258 that was used in his testing that it did not actually increase input lag. I'm willing to bet that it has something to do having a lack of dedicated hardware for the GPU to talk with like the gsync module so the monitor can't show a steady fps value. Even Gsync monitors with frame counters aren't 100% perfect in this regard but they're not as bad as the freesync monitors, but again its just visual and not actually adding input delay unless someone else has tested another monitor and actually found it to be causing delay. Maybe they can fix this on the driver level in future drivers, but so long as its not actually causing added delay its really a non issue.