Stuttering/slugish feeling when FPS drops below FPS Cap G-sync

[Nobody245]

The reason you have "butter smoothness" when running a steady 140 FPS, is the because the limit is the framerate cap you set, which means your system has performance overhead, so there is no CPU or GPU limitation. However, when it drops below your 140 FPS limit, it means it is now instead limited by either your CPU or GPU capability.

I was just going to make a New Topic about this, but might as well not encumber the forum and ask here.

I use an ASUS PG348Q and when my frame rate drops below my FPS cap (98 since refresh rate is 100hz), I experience something akin to the issue described here, although in my case, my feeling is that, mainly, the camera blur becomes excessive/annoying, when I rotate the camera horizontally in 3rd person games, everything that is not my character just blurs too much. Although neither my CPU or my GPU is nowhere near 100%, I use an i9-10900K and an RTX3090(3080 was impossible to buy where I live and I really wanted to upgrade...). I use RivaTuner overlay to monitor. So I do have overhead. Is my case the same as described here? Or is it something different? Or am I hypersensitive to blur?

Additionally, regarding overhead, isn't it possible to reach a maximum frame rate without hitting CPU/GPU limitations? I don't think I've ever seen my system under anything close to 100% load, CPU or GPU, and nevertheless, when I sometimes unlock frame rate for fun, just to see how far it can go, it doesn't exactly blow through the roof and system usage doesn't reach 100%. I'm asking this mainly because I plan on getting a higher HZ monitor (165HZ), but I'm pretty sure I won't be able to hit 163FPS in most games I play. Do I have to account for that and pick a monitor with a refresh rate closer to the average frame rates I get in games I play regularly to avoid potential issues?

[dz520]

I can't comment on the blur.

But just because your CPU is not at 100% usage, doesn't mean it's not a bottleneck in your specific games.
Because most games won't utilize all 20 of your CPU threads, if the game takes up your usual 8-12 threads then your CPU could be at like only 40% usage and still be a bottleneck because of its limiting single threaded performance.

When a GPU is the bottleneck, then you can easily tell by the very high, near-100% usage, but CPUs are a bit different because games load individual cores more rather than the entire CPU evenly, hence you'll never see a 100% CPU usage ingame on CPUs with lots of cores.
You don't even need to have specific cores at 100% usage to be CPU bottlenecked.

The easiest way to tell you're CPU bottlenecked is by observing GPU usage.
If the GPU usage/load is not maxing out in the 90-100% range, then it's the CPU.
If your CPU was faster, then GPU usage would shoot up along with it.
(This is a very simplified explanation.)

Relating to a faster monitor, since you pretty much have the most powerful hardware available right now, the frames you'll be hitting depend on the game and in-game settings.
So you'll have to find balance of good visuals and higher framerates. But I would say that 100 to 165hz would be a great upgrade, I know that comparing 100 and 144hz was already a very noticeable difference for me.
And even if you can't hit those higher framerates in some games, you can still easily lock the FPS to whichever number you feel works the best in terms of smoothness.

[jorimt]

I use an ASUS PG348Q and when my frame rate drops below my FPS cap (98 since refresh rate is 100hz), I experience something akin to the issue described here, although in my case, my feeling is that, mainly, the camera blur becomes excessive/annoying, when I rotate the camera horizontally in 3rd person games, everything that is not my character just blurs too much.

Although neither my CPU or my GPU is nowhere near 100%, I use an i9-10900K and an RTX3090(3080 was impossible to buy where I live and I really wanted to upgrade...). I use RivaTuner overlay to monitor. So I do have overhead. Is my case the same as described here? Or is it something different? Or am I hypersensitive to blur?

From the way you are describing it, your case would be different. The OP was experiencing frametime spikes and stutter related to performance limitations stemming from the system and/or game engine.

Dropping from 100 FPS to 98 FPS should not affect display-derived motion blur to the point of perception.

While performance can be indirectly tied to blur from a large drop in framerate due to an increase in image persistence on a sample and hold-type (LCD) display, motion blur on LCD monitors is affected by two things; GtG blur and image persistence blur.

The first, GtG (gray to gray), is due to the pixel transition time of the panel, I.E. how fast it takes each pixel to change from one shade to the other. The higher the GtG, the more potential for pixel smearing during motion. The lower the native GtG of the panel, the less there will be, and this is further reduced by overdrive, which overvolts the pixels to speed up transition time. However too much overdrive can create overshoot/inverse ghosting instead, so the mid overdrive setting on a monitor is usually the most balanced.

The second, image persistence, is primarily due to the sample and hold nature of LCDs, where, without some form of strobing enabled, each frame will display directly over another, and since frame display isn't instant (frames scan in a pixel at a time, top to bottom, left to right), the previous frame will linger long enough to create an overlapping effect with the next, causing the appearance of a doubling image. The lower the framerate, the longer the previous frame lingers, as the space of time between it and the next frame increases (30 FPS is a new frame every 33.3ms, whereas, say, 100 FPS is a new frame every 10ms, etc).

Finally, the third form of blur, especially in third person games, can be due to post process motion blur at the engine-level, which is intentional, however, and most games obviously allow you to disable it.

Additionally, regarding overhead, isn't it possible to reach a maximum frame rate without hitting CPU/GPU limitations?

Yes, sometimes the game engine itself is CPU and/or GPU-limited, and it can even vary by scene at any given point. This can layer with any system-level CPU/GPU-limitation (if present) as well.

I plan on getting a higher HZ monitor (165HZ), but I'm pretty sure I won't be able to hit 163FPS in most games I play. Do I have to account for that and pick a monitor with a refresh rate closer to the average frame rates I get in games I play regularly to avoid potential issues?

Depends on whether you typically use V-SYNC, G-SYNC, or no sync. If you use G-SYNC or no sync, the higher the native max refresh rate, the better, regardless of achievable framerate (as frames can then scan in faster the higher the Hz), but there can be exceptions, such as higher Hz monitors that don't have as good as overdrive performance as lower Hz monitors, etc.

[Nobody245]

From the way you are describing it, your case would be different. The OP was experiencing frametime spikes and stutter related to performance limitations stemming from the system and/or game engine.

Dropping from 100 FPS to 98 FPS should not affect display-derived motion blur to the point of perception.

The display-derived motion blur becomes noticeable when frame rate drops approximately 10 frames below cap. That is, when it drops to 88 frames or less. Below 80 it starts becoming annoying. Sorry, I did not state this clearly enough in my original post.

Thank you for the detailed explanation, it's appreciated! And it gives me a good idea regarding things!

I use g-sync and have it configured in accordance with your guide. Overdrive is set to the middle value, yes.

Sadly, a bunch of games I like are ports of console jrpg that lack lots of common graphics options, Final Fantasy 14 has no blur-related option at all for example, with the exception of an option to disable something they call radial blur (only game I've seen that option in).

Thanks for guiding me! I'll look into higher HZ monitors.

[jorimt]

The display-derived motion blur becomes noticeable when frame rate drops approximately 10 frames below cap. That is, when it drops to 88 frames or less. Below 80 it starts becoming annoying. Sorry, I did not state this clearly enough in my original post.

Yes, anything around 80 Hz or below is where the lower refresh/framerate makes fluidity visibly suffer vs. say 85 Hz and up (anything at or above the 90 Hz range begins to feel/look more similar than not).

However, since this reduction in fluidity is due directly to less updates per second from a lower framerate, the only "fix" is to either maintain a framerate above that range, or prevent the direct comparison of it against higher FPS/Hz by limiting the framerate to your system's lowest maintainable average in the given game, which will allow your perception to normalize by keeping said average a constant (I.E. you can get "used to" the appearance of 30 FPS as long as it stays there).

G-SYNC obviously won't fix this either, as it adjusts the refresh "rate" by changing how many times the display refreshes per second; if you have 80 FPS, it refreshes 80 times per second, 60 FPS, 60 times per second, etc.

G-SYNC does however retain how fast each of those refresh cycles complete in 1 second, though, so while, say, 80 FPS @144Hz G-SYNC is still running at an effective 80 Hz, each frame is scanning in at 6.9ms per instead of the 12.5ms per it would be at a native 80Hz, which reduces overall input lag at that same framerate. But no, G-SYNC can't make a lower framerate look like a higher one.

Sadly, a bunch of games I like are ports of console jrpg that lack lots of common graphics options, Final Fantasy 14 has no blur-related option at all for example, with the exception of an option to disable something they call radial blur (only game I've seen that option in).

Right, some devs unfortunately bury their motion blur parameters in config files, or don't offer the option disable it at all.

[Nobody245]

Thank you for the detailed explanation! It's really appreciated!

[jorimt]

Thank you for the detailed explanation! It's really appreciated!

No worries.

[biggydeen]

Just an update to verify that I found the rootcause of my problem. Hopefully this will help others with the same issues.

The "unsmoothness" and "stuttering" that i'm experiencing in almost any game at every system (no matter the hardware used) and regardless of FPS way above 120 + G-sync is all related to 1% lows. The tricky part is that 1% lows can be caused by many sources like the CPU/GPU/OS or the game engine itself.

In the specific case of Battlefield and other MP games which are very taxing on the CPU, reducing 1% lows by getting the max out of my CPU did fix the problem. I was aware that my current 5800x is pretty sensative to memory speed and latency. While the 5800x has better overal avg FPS vs recent Intel CPU's, Intel has better 1% lows and that is mostly related to the way Intel CPU's and memory working together. The memory/cpu latency on Intel systems is significantly lower vs Ryzen systems. Not resulting in higher or avg FPS but is resulting in higher 1% lows. Which is way more important then avg fps if you want buttersmooth gameplay.

Since I was running 16GB 3200CL14 memory, this was causing severe bottlenecks for my CPU in terms of 1% lows. Bumping up memory speed increases the infinity fabric and will reduce memory/cpu latency. This will result in huge gains in 1% lows. Besides memory speed, Ryzen is also very sensative to dual rank vs single rank memory. Dual rank memory will significantly improve performance on Zen3. Although it depends on the games and resolution you play.

My 3200CL14 @1.35V is only single rank. But I did manage to overclock to 3800CL16 @1.4V with tight subtimings. I might even get CL14 with even tighter subtimings @ 1.5V but that is something I might look at later on. The results are pretty huge:

In Battlefield 1 & V when running @ 3200CL14 I had to cap FPS to 130 or even lower for buttersmooth gameplay (running a 3080TI). Eventhough my avg fps was way above 150-180, FPS would frequently drop below 130 causing stuttering and unsmooth gameplay. This is very notacible and distracting. Even just a few FPS below cap will introduce these issues. With mem bumped up to 3800CL16 running infinity fabric in 1:1:1 ratio I can set my FPS cap to 140 and it does not even drop below 140fps anymore. Now it's hard to make any performance baseline based on multiplayer games but in Battlefield 1 my FPS would drop all the way down to 120 on the map "Amiens" in certain area's. With the OCéd memory it does not even drop below 140 the entire match. I also noticed that the bigger maps are now buttersmooth @ 140fps while before (@130fps) it was very noticable my system could not hold 130fps. The gains are huge...

I will even get more gains bumping up to 32GB dual rank 4000CL14 (though this is certainly no guarantee that zen3 can run 2000mhz infinity fabric in 1:1:1 ratio or get 4000CL14 mem because you need to manally tune this). You have to be lucky with bins on CPU and mem to run this.

My final recommendation would be the following:

- Hardware: make sure you have the best ram speeds and setup matching your cpu (Intel or AMD). This will have huge impact on 1% low's in CPU bound games (games like Battlefield (2042), Warzone, Pubg, Escape from Tarkov and any MMO)
- Software: make sure your OS is fully optimized without bloatware. Disable most things you don't need. This way you reduce CPU and memory load while gaming
- Buttersmooth gameplay is only possible when you can feed your monitor a steady feed of frames without any drops or fluctuation. G-sync will never fix stuttering caused by 1% lows (framespikes).
- I would recommend following the G-sync 101 guide and setting a fps cap at 1% lows if you want that buttersmooth gameplay.
- If you can't upgrade your system for whatever reason then simply lower graphical settings.

There are some caveats though. High speed ram does not have any impact if you are GPU bound. You wont notice any difference between cheap 3200mhz mem with lose timings vs very expansive 4000mhz with tight timings. Sometimes your monitor can also be causing problems regardless of your settings and setup. But, i'm no expert on the monitor side of things. And in some cases you can have the best system in the world, framespikes still occur due to the game engine or whatever reason. Buttersmooth gameplay is not guaranteed in every game.

Trust me on this, i've been battleling this issue for many years. I never understood why I had so many stuttering issues on many games and completely different hardware. I spend hundreds of hours installing and finetuning software, messing with every game setting, looking into my graphic settings, buying g-sync montiors, upgrading hardware and starting forums posts all over the place...Even the g-sync 101 guide did not solve my problem. So I was thinking it's just me. I'm to sensative to this. These guy's tested everything they can't be wrong right? The subtle difference was I did not need to set my FPS cap 3-4 fps below my max refresh rate but set the cap @ 1% low.

Even the best gaming machine you can buy will have these problems. I actually have one of the beste gaming systems money can buy and I still had these problems... Because of the simple reason the system needs to feed your monitor with consistent frames. Even just 1 fps below cap can cause inconsitancy resulting in graphical issues like stuttering you can certainly notice. Even if your avg fps is way above 120. Just to make clear, you will never see any difference beween a steady fps of 140 vs 135. It's the fluctuation of frames that is causing the issue.

It just never hit me it was about 1% lows all these years. I was only looking at achieving higher fps. And although I upgraded my system many times, higher fps never fixed the problem. Setting a FPS cap @ 1% low did.

[RealNC]

My 3200CL14 @1.35V is only single rank. But I did manage to overclock to 3800CL16 @1.4V with tight subtimings. I might even get CL14 with even tighter subtimings @ 1.5V but that is something I might look at later on. The results are pretty huge:

3800 might actually be slower than 3600 on Ryzen. The fclk mismatch can cause overhead. From I've seen, people need reach RAM speeds well over 4000 to actually counteract the overhead.

So maybe try 3600 instead to get 1:1 clocks.

[mj_rl]

It just never hit me it was about 1% lows all these years. I was only looking at achieving higher fps. And although I upgraded my system many times, higher fps never fixed the problem. Setting a FPS cap @ 1% low did.

How do you know what is your 1% Lows ?

EDIT : Found a video about it (https://www.youtube.com/watch?v=gkv4gg0kM4U for those interested).

Now my noob question is :
[1] Why do I have 222 FPS 1% Lows with Uncapped FPS, [2] and when I cap my FPS on RTSS at 222% my 1% Lows is 196 FPS, [3] when I cap them at 196 FPS my 1% Lows become 181 ?