Capping FPS with VSYNC OFF

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Hexadecimal
Posts: 9
Joined: 27 Apr 2014, 01:21

Capping FPS with VSYNC OFF

Post by Hexadecimal » 05 Jul 2014, 04:51

Hey everyone,

I have run into this very specific problem. I play League of Legends at one of the highest levels competitively and so it's very important that hardware or settings isn't holding me back and for me to get every advantage I can.

Right now I have a 144hz BenQ XL2420Z monitor and good hardware. When I play League of Legends I have it uncapped and I get 400+ FPS at the start of the game that lowers to around 220 FPS as the game progresses. Now, here's my problem, right now if I get more than 370 FPS it causes my character to "skip" around, sometimes even other characters - this is completely unacceptable for competitive gaming. This only effects the start of the game as eventually my FPS will drop lower.

Essentially, for what ever reason if I have more than 350-370 fps it causes my character and sometimes other characters to "skip" and jitter/teleport, which makes hitting your abilities or predicting them extremely difficult. League of Legends only has the option to cap FPS in-game at 80 fps. Obviously since I'm using a 144hz monitor capping at 80 fps won't work for me. There's no way to edit the config file and create a custom fps - I checked.

So my only option is to cap my FPS using software such as nVidia Inspector to prevent it from surpassing that 350-370 fps mark. However, I'm extremely worried about causing input lag doing this. I tried searching the forums and online and couldn't find a definitive answer to my questions. Does using a software to cap your FPS cause input lag when using V-SYNC off?

I refuse to enable v-sync to fix this issue because of the input lag. Does anyone know how I can fix this issue? This has been an issue with League of Legends for over 2 years so they won't be fixing it themselves. Anyways, here's a conclusion to what my problems:

-I play League of Legends at one of the highest levels
-I have 144hz Monitor and a great gaming rig
-League of Legends has an issue where if you surpass 350 FPS it can cause characters in the game to stutter and skip around
-I need a way to cap my fps so it doesn't surpass this 350 FPS mark to prevent this stuttering, however there are no options within the game to do this
-The only option I'm aware of is to use software such as nVidia Inspector, but I'm worried it will cause input lag

Will using software such as nVidia Inspector to cap my FPS with V-Sync OFF cause input lag?
Does capping your FPS with V-Sync OFF in general cause input lag?

There's just so much information, misinformation, terms, and concepts - I'm just simply not able to solve this problem on my own. I would really appreciate an expert from this forum to tell me how to solve this problem as it's been driving me crazy. Any help is greatly appreciated!

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RealNC
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Re: Capping FPS with VSYNC OFF

Post by RealNC » 05 Jul 2014, 06:30

No, there's no input lag when capping with vsync off.

You can add a custom FPS cap to Inspector. For example you can add a 250FPS cap. To do that, go to the directory of inspector and open the file "CustomSettingNames_en-EN.xml" with notepad or whatever text editor you're using.

Search for "Frame Rate Limiter". This will find this:

Code: Select all

      <UserfriendlyName>Frame Rate Limiter</UserfriendlyName>
      <HexSettingID>0x10834FEE</HexSettingID>
      <MinRequiredDriverVersion>280.26</MinRequiredDriverVersion>
      <Description />
      <GroupName>Common</GroupName>
      <SettingValues>
        <CustomSettingValue>
          <UserfriendlyName>Off</UserfriendlyName>
          <HexValue>0x00000000</HexValue>
        </CustomSettingValue>
        ... list goes on ...
After the last FPS cap entry and before the first temperature cap entry, add another entry that looks like this:

Code: Select all

        <CustomSettingValue>
          <UserfriendlyName>250 fps</UserfriendlyName>
          <HexValue>0xF00000FA</HexValue>
        </CustomSettingValue>
You can use any other value you want by changing the hex value. For example, if you want a 200FPS cap instead, then convert the number 200 to hex. That's "C8". Then use:

Code: Select all

<HexValue>0xF00000C8</HexValue>
Note that the "<UserfriendlyName>" entry is simply the text that's displayed in inspector. It doesn't affect the actual cap value. Only the "<HexValue>" entry affects the cap.
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Hexadecimal
Posts: 9
Joined: 27 Apr 2014, 01:21

Re: Capping FPS with VSYNC OFF

Post by Hexadecimal » 05 Jul 2014, 19:55

Thanks for your reply it was very helpful.

If capping doesn't cause input lag then why don't people do it? Wouldn't this result in a more consistent experience and tax your GPU less?

Let's say someone gets 550 to 650 fps and it's constantly varying between there. Wouldn't it be better to just cap at 500 fps since the difference of 50-150 fps you would be getting at the 500+ fps mark wouldn't be noticeable by the human eye? Wouldn't the benefits of having a static FPS outweigh the 50-150 fps gain you would get at an already extremely high fps mark?

I also thought that the hype around G-Sync was that it synced your fps and refresh rate without input lag. If people can just cap their fps with a program like nVidia Insepctor why wouldn't they just cap it at their refresh rate and get the benefits of the new G-Sync technology? I'm still a bit confused.

What are the downsides of capping your fps with a program like Inspector? There has to be some downsides or else everyone would do it and G-Sync would be obsolete. Also, what's the most optimal way of capping your fps? Should you cap it at your refresh rate or 1-3 frames below it? Should you just cap it slightly below your computers max FPS in order to reduce variance and have a consistent frame rate?

Any help is much appreciated.

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RealNC
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Re: Capping FPS with VSYNC OFF

Post by RealNC » 05 Jul 2014, 21:04

Hexadecimal wrote:If capping doesn't cause input lag then why don't people do it? Wouldn't this result in a more consistent experience and tax your GPU less?
With vsync off, the higher the FPS, the better, otherwise tearing becomes a problem, since the visibility of tearing increases as the framerate gets lower. Also, not everyone cares about power usage. That's we buy big coolers for the GPU :-)

But generally, if a system can ouput more then about 300FPS, then yes, capping makes sense since at that framerate, tearing is almost not perceivable at all. How I don't know of many machines that can reach 300FPS with most modern games. More often than not, high-end systems hover around 80-150FPS with demanding games. I'd like to see the PC that can run CoD and BF at 600FPS...
Let's say someone gets 550 to 650 fps and it's constantly varying between there. Wouldn't it be better to just cap at 500 fps since the difference of 50-150 fps you would be getting at the 500+ fps mark wouldn't be noticeable by the human eye? Wouldn't the benefits of having a static FPS outweigh the 50-150 fps gain you would get at an already extremely high fps mark?
It doesn't make a difference, unless the game has problems (like in your case.)
I also thought that the hype around G-Sync was that it synced your fps and refresh rate without input lag. If people can just cap their fps with a program like nVidia Insepctor why wouldn't they just cap it at their refresh rate and get the benefits of the new G-Sync technology? I'm still a bit confused.
Because of tearing and stuttering. Capping doesn't help anything. Capping your framerate so that it matches the refresh rate doesn't mean that the frames are synced to the monitor. They are not. They are only synced when you enable vsync.
What are the downsides of capping your fps with a program like Inspector? There has to be some downsides or else everyone would do it and G-Sync would be obsolete.
I don't think you understand what G-Sync does :) Capping the framerate does not result in the frames being synced to the monitor. You still get tearing.
Also, what's the most optimal way of capping your fps? Should you cap it at your refresh rate or 1-3 frames below it? Should you just cap it slightly below your computers max FPS in order to reduce variance and have a consistent frame rate?
Capping 1-3 FPS below refresh is done to reduce input lag when vsync is enabled. External cappers cannot reduce input lag with vsync is on and you're capping to the the same value as the refresh rate. And with vsync off, there's no point in capping below the refresh rate.

The most optimal way to apply a framerate cap is by the game itself. If the game has an internal framerate limiter, then using it will in most games minimize input lag when vsync is enabled. When vsync is disabled, input lag is only slightly worse with an external limiter. Using an internal one is still preferred. But if the game doesn't have one, then you don't need to worry about it. At the framerates you're using (250+), there won't be any significant input lag when capping externally.
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Hexadecimal
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Joined: 27 Apr 2014, 01:21

Re: Capping FPS with VSYNC OFF

Post by Hexadecimal » 06 Jul 2014, 07:17

Thank you for taking the time to reply, your explanations were extremely helpful.

Aruzom
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Joined: 20 Sep 2014, 19:21

Re: Capping FPS with VSYNC OFF

Post by Aruzom » 22 Oct 2014, 05:43

RealNC wrote:No, there's no input lag when capping with vsync off.
What about Chief Blur Buster's post http://forums.blurbusters.com/viewtopic.php?f=10&t=895
Or is that only with V Sync enabled?

flood
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Joined: 21 Dec 2013, 01:25

Re: Capping FPS with VSYNC OFF

Post by flood » 22 Oct 2014, 18:58

depends on definition of input lag but generally if your fps is high enough (e.g. >150) it's nothing to worry about for 90% of games

see this image i made a while ago
http://i.imgur.com/9cSP1bM.png

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