Vertical Sync

[torus]

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.

[divVerent]

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.

[FruitieX]

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 .

[divVerent]

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).

[morfar]

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.

[divVerent]

m_filter 0?

[morfar]

m_filter is 0. I hated m_filter 1 since CS
m_filter 1 is for sure worse when I tested it.

[esteel]

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

[morfar]

If you have mouse input problems.. vsync might be the reason..

lol, I know vsync is the reason, or else I would not post And that's why I will not use vsync.

[esteel]

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.