Vertical Sync

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Tue Jun 12, 2007 2:03 am

  • Why does vertical sync, more than anything else, hit the performance of Nexuiz so much on my machine? On Stormkeep, I get a pretty steady 200-300fps with average everything, no v-sync, and a rock solid 60 fps with it on. And I mean solid- it never dips below 58, and then only for a nearby rocket blast or eggs and bacon. What gives? I don't really notice a difference.
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    torus
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Tue Jun 12, 2007 6:20 am

  • That's exactly the purpose of vertical sync. It means that the game doesn't calculate more pictures than your screen can display, so it reduces CPU and GPU load (and heat) and ensures that there is no "tearing" on the screen which happens when uploading too many images.
    1. Open Notepad
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    You can vary the number of "MS", so you can clearly see it's MS which is causing it.
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    divVerent
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Tue Jun 12, 2007 7:24 am

  • I can recommend to use vsync at all times at least if you have an LCD monitor. They aren't capable of displaying that many images per second (Mine ranges from 60-75). It's no use with 300 frames per second if the monitor can only render 75 of them per second. The tearing that div0 talked about happens when the monitor is rendering a new image and then suddenly gets another image to render before finishing the first image. Then half of the screen will be the first image and the other half will be the second image. This is easily discoverable if you disable vsync and turn around in some place with big color differences. You will see what "tearing" is then :).
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    FruitieX
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Tue Jun 12, 2007 8:35 am

  • Actually, I see no reason to disable vsync other than if the graphics driver is also forcing vsync and you'd get half the fps (like 30fps constant) because it syncs twice each frame (happens with some buggy drivers apparently). There is no reason to render more than you can display, and vsync results in more idle time "for free" (that is, less CPU and GPU heat).
    1. Open Notepad
    2. Paste: ÿþMSMSMS
    3. Save
    4. Open the file in Notepad again

    You can vary the number of "MS", so you can clearly see it's MS which is causing it.
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    divVerent
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Tue Jun 12, 2007 9:05 am

  • I would use vsync because I have a LCD screen, BUT the mouse movements gets delayed strangely. I will try -dinput and see if that helps.
    No it didn't help.
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    morfar
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Tue Jun 12, 2007 9:18 am

  • m_filter 0?
    1. Open Notepad
    2. Paste: ÿþMSMSMS
    3. Save
    4. Open the file in Notepad again

    You can vary the number of "MS", so you can clearly see it's MS which is causing it.
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    divVerent
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Tue Jun 12, 2007 10:29 am

Tue Jun 12, 2007 12:48 pm

  • If you have mouse input problems.. vsync might be the reason.. there are basicly three modes you can choose from:

    - no vsync: as said it renders as many frames as possible, high usage of cpu/gpu and produces tearing because the frames are not synced

    - vsync with double buffering: prevents tearing but a problem arises IF your computer dips under the sync rate. Lets asume its 60hz, if fps do down to 55fps, the syncing causes fps to instead go down to 30fps and reuse each frame twice. That huge fps drop can be very evil but with the new engine in 2.3 and some tweaks that should never happen.

    -vsync with triple buffering:prevents tearing but because of the three buffers it uses even more graphics ram and the three buffers also cause a slight input lag as it will display one old frame, wait to display the second buffer and render the new frame with the input action into the third buffers which can give you up to 3 frames input lag. Maybe try to disable the triple buffering in the video drivers.

    http://en.wikipedia.org/wiki/Triple_Buffering
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    esteel
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Tue Jun 12, 2007 3:34 pm

  • esteel wrote:If you have mouse input problems.. vsync might be the reason..

    lol, I know vsync is the reason, or else I would not post :P And that's why I will not use vsync.
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    morfar
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Tue Jun 12, 2007 7:19 pm

  • Yeah but it could help if you switch to double buffering..

    Well some other games were the physics depend on the fps (like quake3 and stuff based on it) are an other reason to NOT use vsync.. In Q3 you jumped slightly higher (and thus farer) if you had 'magic' fps values.
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    esteel
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Wed Jun 13, 2007 7:52 am

  • 132 on internet and 142 on LAN iirc :P
    "One should strive to achieve; not sit in bitter regret."
    WE ARE NEXUIZ.
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    C.Brutail
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Wed Jun 13, 2007 12:30 pm

  • There was a whole bunch of numbers but yeah 132/142 were the most commonly used as those had the 'best' results and the rigs back then could do those fps when tweaked. I think there are some more HIGHER fps numbers that might result in higher jumps (if it were real live in the mm range :) )
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    esteel
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Mon Jun 18, 2007 4:14 pm

  • I tried using vsync but after a few days (indeed, it worked fine at first O_o) I'm getting a kind of flickering effect that's way more annoying (and consistent) than tearing. But I'd still like to limit my frame rate, especially now that summer heat is starting to melt stuff all around me :)
    So, my question is, does Nexuiz have some cvar like q3's /com_maxfps or vsync is the only way to limit fps?
    Or, does anyone know how to enable triple-buffering on OS X?

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    800A
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Mon Jun 18, 2007 4:20 pm

  • 800A wrote:So, my question is, does Nexuiz have some cvar like q3's /com_maxfps or vsync is the only way to limit fps?

    cl_maxfps (same as in q1)
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