G-sync refresh rate/fps question.(long read)

[wiseude]

I have a 4 year old dell S2721DGF and today I noticed that even tho I have all the g-sync setting enabled (in the Nvidia control panel and the monitor settings) the refresh rate was not aligning with the fps ingame.I managed to figure it out and I had to turn off the AMD freesync premium pro setting in the monitor settings and re-enable it and the refresh rate started matching again.

One thing I noticed is the refresh rate is trying to align with the fps but it's a bit erratic and can't match the fps perfectly.For example I'd be playing a game and I would be holding a stable'ish 105 fps but the refresh rate wouldn't hold exactly 105 fps (it tries and its close to it) and when looking around I'd even see a 5-15fps up/down variance for a split second even if I had a 100-105 stable fps
Is this normal?

[RealNC]

One thing I noticed is the refresh rate is trying to align with the fps but it's a bit erratic and can't match the fps perfectly.For example I'd be playing a game and I would be holding a stable'ish 105 fps but the refresh rate wouldn't hold exactly 105 fps (it tries and its close to it) and when looking around I'd even see a 5-15fps up/down variance for a split second even if I had a 100-105 stable fps
Is this normal?

It's normal. It also depends on the accuracy of the frame limiter you're using. Nvidia's limiter has some variance that results in more fluctuation compared to SpecialK's "Normal" limiter mode, for example. You don't need to care about that unless you're trying to reduce VRR flicker (on OLED display's, for example.)

[wiseude]

One thing I noticed is the refresh rate is trying to align with the fps but it's a bit erratic and can't match the fps perfectly.For example I'd be playing a game and I would be holding a stable'ish 105 fps but the refresh rate wouldn't hold exactly 105 fps (it tries and its close to it) and when looking around I'd even see a 5-15fps up/down variance for a split second even if I had a 100-105 stable fps
Is this normal?

It's normal. It also depends on the accuracy of the frame limiter you're using. Nvidia's limiter has some variance that results in more fluctuation compared to SpecialK's "Normal" limiter mode, for example. You don't need to care about that unless you're trying to reduce VRR flicker (on OLED display's, for example.)

In this case I have no fps limiter because I don't hit my refresh rate cap with the games I play so im always in the g-sync zone as I understand it.I only have v-sync-gsync enabled.

Also thank you for the fast response.I was getting worried because I was seeing some significant variability between fps/refresh rate and from my understanding the refresh rate/fps was supposed to be constantly 1:1.Now that I know it's normal to have some variability it gives me peace of mind.I thought there for a second I had a defective monitor that couldn't hold 1:1 fps/refresh rate.

[hamsterman]

Hey, may I ask what CPU/GPU you got? I have the exact same monitor and trying to set it up over the last few years has hurt my head. Some games I have the same problem, one game more than others. I have gsync and vsync on in nvcp aswell as ULL if reflex is not inside the game. I put all graphics on low to ensure i reach 158 fps but sometimes my frames would drop below 140 randomly which is causing game stutter, any idea whats up with that?

[jorimt]

i reach 158 fps but sometimes my frames would drop below 140 randomly which is causing game stutter, any idea whats up with that?

Frametime spikes:
https://blurbusters.com/gsync/gsync101- ... ettings/2/

What are Frametime Spikes?

Frametime spikes are an abrupt interruption of frames output by the system, and on a capable setup running an efficient game engine, typically occur due to loading screens, shader compilation, background asset streaming, auto saves, network activity, and/or the triggering of a script or physics system, but can also be exacerbated by an incapable setup, inefficient game engine, poor netcode, low RAM/VRAM and page file over usage, misconfigured (or limited game support for) SLI setups, faulty drivers, specific or excess background processes, in-game overlay or input device conflicts, or a combination of them all.

Not to be confused with other performance issues, like framerate slowdown or V-SYNC-induced stutter, frametime spikes manifest as the occasional hitch or pause, and usually last for mere micro to milliseconds at a time (seconds, in the worst of cases), plummeting the framerate to as low as the single digits, and concurrently raising the frametime to upwards of 1000ms before re-normalizing.

G-SYNC eliminates traditional V-SYNC stutter caused below the maximum refresh rate by repeated frames from delayed frame delivery, but frametime spikes still affect G-SYNC, since it can only mirror what the system is outputting. As such, when G-SYNC has nothing new to sync to for a frame or frames at a time, it must repeat the previous frame(s) until the system resumes new frame(s) output, which results in the visible interruption observed as stutter.

The more efficient the game engine, and the more capable the system running it, the less frametime spikes there are (and the shorter they last), but no setup can fully avoid their occurrence.

G-SYNC cannot affect or improve system performance, but system performance can affect G-SYNC.

Frametime spikes occur with or without G-SYNC, V-SYNC or framerate limiters.

[hamsterman]

i reach 158 fps but sometimes my frames would drop below 140 randomly which is causing game stutter, any idea whats up with that?

Frametime spikes:
https://blurbusters.com/gsync/gsync101- ... ettings/2/

What are Frametime Spikes?

Frametime spikes are an abrupt interruption of frames output by the system, and on a capable setup running an efficient game engine, typically occur due to loading screens, shader compilation, background asset streaming, auto saves, network activity, and/or the triggering of a script or physics system, but can also be exacerbated by an incapable setup, inefficient game engine, poor netcode, low RAM/VRAM and page file over usage, misconfigured (or limited game support for) SLI setups, faulty drivers, specific or excess background processes, in-game overlay or input device conflicts, or a combination of them all.

Not to be confused with other performance issues, like framerate slowdown or V-SYNC-induced stutter, frametime spikes manifest as the occasional hitch or pause, and usually last for mere micro to milliseconds at a time (seconds, in the worst of cases), plummeting the framerate to as low as the single digits, and concurrently raising the frametime to upwards of 1000ms before re-normalizing.

G-SYNC eliminates traditional V-SYNC stutter caused below the maximum refresh rate by repeated frames from delayed frame delivery, but frametime spikes still affect G-SYNC, since it can only mirror what the system is outputting. As such, when G-SYNC has nothing new to sync to for a frame or frames at a time, it must repeat the previous frame(s) until the system resumes new frame(s) output, which results in the visible interruption observed as stutter.

The more efficient the game engine, and the more capable the system running it, the less frametime spikes there are (and the shorter they last), but no setup can fully avoid their occurrence.

G-SYNC cannot affect or improve system performance, but system performance can affect G-SYNC.

Frametime spikes occur with or without G-SYNC, V-SYNC or framerate limiters.

Thank you. I guess I just assumed everything should run smoothly but essentially what you posted above makes it sound like the occasional stutter is normal, especially if the game isn't optimized I guess.

If a specific game is causing random stutters would there be any downside to maybe capping my fps lower to around 144 for example despite having gsync and vsync enabled? I just want to try and have the smoothest possible gameplay and avoid any type of stuttering. I put everything on lowest graphical settings and the frame spikes still happen which doesn't make sense to me. I have a 5800x and 3070 and usually the cpu usage is higher than gpu so I guess it's a bottleneck? I have no idea how to work around this.

If it is ok to cap down to 144 fps despite running 165hz monitor how would gsync and vsync come into this because the game has reflex and it caps my fps automatically.

I've pretty much tried everything to eliminate the problem. From having nothing open in background to removing any software related to my mouse/keyboard. Even DDU my drivers and started fresh. Done benchmarks via 3dmark and tested my RAM and checked internet, everything as far as I know is how it should be.

[jorimt]

If a specific game is causing random stutters would there be any downside to maybe capping my fps lower to around 144 for example despite having gsync and vsync enabled? I just want to try and have the smoothest possible gameplay and avoid any type of stuttering.

Lowering your average framerate will not reduce or prevent frametime spikes since said spikes are already at or near 0.

I put everything on lowest graphical settings and the frame spikes still happen which doesn't make sense to me.

That will just reduce the load on your GPU, so any spikes not directly related to the GPU will still remain.

If it is ok to cap down to 144 fps despite running 165hz monitor how would gsync and vsync come into this because the game has reflex and it caps my fps automatically.

If you apply a manual limit below the automatic Reflex limit that engages when G-SYNC + V-SYNC is enabled, then the lower limit will be the one that applies.

As such, whenever the framerate drops below your manual limit, due to maxed GPU usage, for instance, the dynamic Reflex limiter will take effect again instead, until the framerate can be sustain at/above your manual limit.

I've pretty much tried everything to eliminate the problem. From having nothing open in background to removing any software related to my mouse/keyboard. Even DDU my drivers and started fresh. Done benchmarks via 3dmark and tested my RAM and checked internet, everything as far as I know is how it should be.

You can't 100% prevent frametime spikes, which are heavily game/engine-dependent, and are sometimes ultimately limited by I/O operation (how well/fast data can be swapped from the SSD/HDD to RAM/VRAM).

[RealNC]

Apparently the only game out there in recent years to not have spikes and stutters is KCD2 These days, saying that you're getting stutters and frametime spikes in games is like saying the sky is blue.

https://www.youtube.com/watch?v=w31Ct25gJlI

[hamsterman]

You can't 100% prevent frametime spikes, which are heavily game/engine-dependent, and are sometimes ultimately limited by I/O operation (how well/fast data can be swapped from the SSD/HDD to RAM/VRAM).

Maybe I'm misunderstanding the problem I have. For example I did a raid in World of Warcraft today and 60% of the raid my game just felt like it was stuttering, maybe stuttering is the wrong term but it's not smooth at all. I was checking my gpu and cpu usage and it's completely normal but my fps would drop from 158 to around 100 and then it happens briefly. So I don't know if it is a framerate stutter or something else, it's just not smooth and it's the most irritating thing I have experienced.

If it's not the framerate spike causing the problem what would you suggest I do to try and eliminate this problem once and for all?

I've googled the problem specifically with my hardware and I've tried every possible solution and it just still persists. The only thing I have not done is a fresh windows install, I will consider this in the near future but right now isn't good for me.

Thank you.

[jorimt]

I was checking my gpu and cpu usage and it's completely normal but my fps would drop from 158 to around 100 and then it happens briefly.

If that results in the game looking like it's momentarily visually pausing, that's frametime spikes.

And in that case, It's not only dropping to, say, 100 FPS, it's actually dropping to 0, but system-side framerate counters typically only report every second, so they're behind enough not to reflect the literal drop.

And, no, you don't want the counter to update fully in real-time, or it will cause further performance issues due to pinging too frequently, interrupting the game and other processes.

You instead want to look at the frametime graph; if there's an [x]ms spike, that means the same frame was repeated (aka stutter) for [x]ms until the next new frame was displayed.

If however, what you're experiencing feels more like continual jitter, that's frametime variance (sometimes more commonly referred to as "micro-stutter"), which can be mitigated by ensuring you have a framerate limit set that your system can consistently reach 99% of the time. And if that doesn't fix it, it means the game itself has internal frame pacing issues that can't easily be corrected on the user-side (or at all in some cases).