How to effectively cap your FPS? (capped fps/capping)

[everennui]

It's pretty clear that capping your FPS in a video game can increase the performance to some degree, but I'm not exactly sure how this is done most effectively. I set Doom to the refresh rate of my monitor (vid_maxfps 85 (Default is 200)) and it seems to do well. There's plenty of material on Google regarding this topic, but I can't find any pleb-tier material that explains HOW to do it EFFECTIVELY.

How do you cap your frames?

I was thinking about capping them at the 1% low, but that's quite low in some games. Do I just watch the FPS and shoot a little under the average? What do you need to think about when you do this?

Any reading material you could provide would be helpful. I've read a lot of material about different programs, why it's helpful, opinions, etc. just not how to do it.

[fraggle]

4 hours ago, everennui said:

It's pretty clear that capping your FPS in a video game can increase the performance to some degree,

That doesn't make much sense. We usually use FPS to measure performance.

[everennui]

That may be true, but that's not what you want when you're playing a game. That's good info to have for videogame optimization, checking performance of your system, etc. Maybe it doesn't matter so much for classic Doom as much, but in newer titles, it's extra stress on your CPU and GPU. If you have 100hz monitor and get 120 FPS, you're basically wasting processing power. With higher frame rates, there are more noticeable spikes. This is partly because the average temperature of a GPU that is uncapped will be higher, and that increase in temperature can actually cause thermal throttling.

[Vorpal]

Many applications have configurable fps limits as you say.

 

Some have a vertical sync option, can use that to limit render rate to monitor refresh rate (some people say it introduces input lag? I dunno)

 

nvidia/amd driver suites usually have hacks that let you set "target framerate" on a per application basis

 

Finally, there's 3rd party software that can also accomplish what the driver suites do, but this is the least trustworthy method. MSI Rivatuner springs to mind.

[fraggle]

1 hour ago, everennui said:

If you have 100hz monitor and get 120 FPS, you're basically wasting processing power. With higher frame rates, there are more noticeable spikes. This is partly because the average temperature of a GPU that is uncapped will be higher, and that increase in temperature can actually cause thermal throttling.

Okay, that makes some sense. But still, if it isn't frame rate, what is it that you're trying to optimize?

 

It sounds like what you're actually asking about is consistent performance - you want a stable frame rate that won't occasionally drop out. Thermal throttling might be one reason why that happens, and frame rate throttling might be one way of preventing it, but is it the best solution? There are a whole bunch of ways for controlling temperature, so maybe look into those instead of assuming that "frame rate throttling" is what you want.

 

For example most CPUs/GPUs have built-in features that allow them to run cooler. You can usually configure your CPU to underclock it, or configure your GPU to use fewer cores. You can also sometimes configure the control loop that's used for maintaining safe temperature - if you're comfortable with potentially damaging your system then perhaps increase the maximum temperature, or do the opposite - make it kick in earlier in a less extreme way. Your goal should be to get the highest frame rate while also maintaining a stable frame rate.

[everennui]

3 hours ago, Vorpal said:

Many applications have configurable fps limits as you say.

 

Some have a vertical sync option, can use that to limit render rate to monitor refresh rate (some people say it introduces input lag? I dunno)

 

nvidia/amd driver suites usually have hacks that let you set "target framerate" on a per application basis

 

Finally, there's 3rd party software that can also accomplish what the driver suites do, but this is the least trustworthy method. MSI Rivatuner springs to mind.

IIRC, VSync pretty much adapts to your monitors refresh rate. You'll have lag if your FPS is lower than your refresh rate.

I guess what I'm trying to figure out is how do you find the, "target framerate"... actually that sounds googlable.

 

Quote

frame rate throttling

This should be helpful.

I just don't feel like the average would be good, because that's - obviously - an average of your max and low, so the results would not really tell you anything. Maybe it'd just be better to do 10 FPS below the average. 

I don't even have the video card that I'm concerned about yet. Should be here on Friday.

I jumped on the Ryzen bandwagon, and the CPU I got is a bottleneck for to the graphics card I purchased.

My current computer has a way larger bottleneck from the CPU. As soon as I try to run any "true 3D" my fans start blasting. I'm talking like Quake 3. It's very unstable, but the computers really old and I found a great deal on it from craigslist. It's a really nice EVGA 570HD 2.5G, but it's on a low end Athlon II. Honestly, I haven't had many computers in my life, so I don't know about all this stuff. Before this used 570 the last card I got was a Geforce 4. That probably had some options too, but I am pretty scared to manipulate things on my PC. Some of these buzzwords are really helpful. I should check to see if my GPU has some configuration options (for the 570). On my new card, I intend to know everything about everything - if I can.

I do intend to upgrade my PC over time, but in case I end up with this new computer for 9 years again, I want it to last.

Edited September 12, 2017 by everennui

[Vorpal]

I can only speak for Radeon Settings, where it's under the "Gaming" tab and then the application you want to fiddle with, "Frame Rate Target Control". It doesn't work for all applications, but it's pretty good.

[dpJudas]

13 hours ago, everennui said:

I was thinking about capping them at the 1% low, but that's quite low in some games. Do I just watch the FPS and shoot a little under the average? What do you need to think about when you do this?

Part of the problem here is that the ideal cap depends on a lot of factors. For example, in GZDoom, there's the time it takes to render a frame and then there's the time it takes to tick the playsim. On some mods the playsim time might be 0.1 ms of the total frame with 10 ms spent rendering. Other mods, like BoA, the playsim time might be 10 ms and the render time 4 ms.

 

To get a stable rendering for BoA you need to factor in that the actual frame render times might be 4 ms, 4 ms, 4 ms, 14 ms, 4 ms, 4 ms, 4 ms, 24 ms, 4 ms, etc. What is happening here is that the playsim ticks at 35 hz which means that some frames it only takes 4 ms, some 4 + 10 ms, and occasionally two playsim ticks happen in the same frame causing a nasty 24 ms frame time. End result is that the average frame rate appears fine, but those 24 ms spikes makes it extremely unpleasant to play.

 

Your overall goal here for BoA is thus to cap the fps at something like 26 ms (38 fps) because then the stuttering will be gone. Of course, for other mods this is way too aggressive.

 

Using the 1% low has the problem that this might include stutters you may consider acceptable to encounter (such as a resource load). My advice would be to keep lowering the cap until the stutters that are annoying you go away, without any further scientific approach to it. As illustrated with BoA, you may need to adjust the cap depending on what you're actually playing.

 

(Note: all the numbers for BoA are made up.)

[Nevander]

For me, my FPS ends up capping itself because my PC is a crud.

[Edward850]

24 minutes ago, Nevander said:

For me, my FPS ends up capping itself because my PC is a crud.

This would imply that there is such as thing as infinite FPS (and this would be physically impossible). Every PC must have a framerate cap (within your context of the word cap).