Vsync vs FPS Cap or Both?

[Litzner]

I am running a 144hz monitor at 120hz with LightBoost, there is no Gsync or FreeSync capability in this monitor. I am looking to get optimal FPS response time\input lag a long with my blur reduction. Right now I am not using vSync or a FPS cap, should I be using one or both? If I should be limiting fps should I be doing that at 120? 118?

I also have a 60hz gaming setup, what is the optimal vsync fps cap for that old setup?

[KindOldRaven]

Vsync would result in the best motion blur reduction effect with lightboost probably... but induces input lag. Second best option is probably going for a stable fps cap at your refresh rate. The other option is trying to use 280/300fps cap in games like CSGO if you can hit them... But usually fps=hz=strobing is your most 'clean' option from what I've read here and tested myself.

[RealNC]

Don't frame cap if you don't use vsync. The higher your FPS, the better motion quality you'll get. If tearing and micro-stutter are an issue for you however, then you need vsync, but for the least amount of input lag when using vsync, frame capping is a must. See:

https://forums.guru3d.com/threads/the-t ... st-5380262

and:

https://www.blurbusters.com/howto-low-lag-vsync-on/

[Chief Blur Buster]

Yes, the cleanest smoothest strobed motion occurs at framerate = refreshrate = stroberate.

The Low-Lag VSYNC ON howto is very useful in reducing strobe lag since the VSYNC ON methods really help smooth strobing, but we know there's input lag for VSYNC ON.

[Litzner]

I was reading the low lag vsync article and that turned me on to fast sync. But I found it interesting that fast sync typically recommends a frame rate 2-5x the refresh rate, but the low lag way says to almost sync the refresh and fps, which from what I have read would get you higher input lag.

[Litzner]

I just wanted to mention, I have been doing a lot of research on this site and I wanted to thank you guys for all the time and effort put in it. There is such a wealth of tweaking information here.

I did end up setting up Lightboost+Fast Sync+RTTS fps limit, and I am getting a very smooth experience now, I don't notice any additional input lag, but I don't have the tools to measure it of course. I was curious, right now the game I am playing is very CPU intensive on my machine, specifically at a few locations at a few maps. If my FPS sometimes drops down to the 100-110 range, but is usually locked at 120, would that be a problem with the "Lightboost+Fast Sync+RTTS fps limit" setup?

[RealNC]

If it works for you, then it's fine. You get more microstutter with fastsync, but if it doesn't bother you, then who cares.

[Litzner]

If it works for you, then it's fine. You get more microstutter with fastsync, but if it doesn't bother you, then who cares.

Do you know the rough input lag difference between Lightboost+FastSync+RTTS FPS Cap vs Lightboost+VSync+RTTS FPS Cap?

[jorimt]

It should be roughly the same overall input lag between the two, but each may feel a little different due to the slight differences in frame delivery.

Try both, and pick which feels best.

[Chief Blur Buster]

Similar behavior. Stutter differences will be the main difference.

Ideally we need a future RTSS that dynamically changes the cap automatically to prevent framebuffer backpressure. Achieve perfect 60fps @ 60Hz VSYNC ON with one less frame latency. But we can't do that with RTSS, so we need a fractional difference to keep the backpressure off.