Tearing and v-sync

[magictorch]

Specs of my computer:

3.0Ghz P4
2GB DDR RAM
256MB 9600XT (Overdrive enabled, 4.12 Cats)
Plenty of hard drive space
17" LCD screen

After using some tweaks from www.tweakguides.com and the patch, I was comfortably playing the game on 800x600, high everything (except for medium sound), trilinear filtering, no AA, reflect world. The frame rate was usually around 60-120 fps (though I think my monitor only refreshes at 75hz), but rarely dropped into the 30s and never below. I wasn't experiencing any stuttering whatsoever.

As I played the game more and more I started to notice tearing. I think it was always there but at first I was so in awe of the game/graphics I didn't see it. It really started to bug me. So I enable v-sync. With this on, the frame rate generally stuck at a solid, respectable 60fps, obviously with no tearing. I didn't see it drop below that too many times, though, because stuttering became a lot more apparent. So I switched v-sync off but then the tearing reared it's ugly head again.

I'm hoping v-sync would be more succesful with a higher frame rate (especially as triple buffering isn't supported, as I'd hate to keep seeing the frame rate suddenly drop to 30fps or even 20fps). Can anyone suggest a couple of graphical settings I could lower that would make the best trade-off of improved performance with minimal loss of graphical quality? Also, does anyone know if v-sync will be supported in the future, and if so, will that be enabled by a patch or something?

Cheers for your help!

 

[TEDR]

v sync on synconises your fps to the monitor refresh . there for 60hz refresh = 60fps

if you have 75hz refresh it would = 75fps

 

[TEDR]

Vsync should only be disabled when benchmarking so that the videocard and processor are not being limited by the display. Frame rates will appear higher with vsync off but the amount of information displayed is limited by your monitor in that instance. A monitor with an 85 Hz refresh rate will only display 85 frames per second even if the videocard is rendering 400 frames a second. The visual quality may decline as a result also because some frames could be skipped as a result of excess rendering so the interpolation between the first frame and the next frame displayed could be off resulting in 'tearing' or jerkiness

 

[maniac618]

so if i have a 60hz monitor i should cap fps to 60 or just throw vsync on?

 

[TEDR]

if you put vsync on it will cap to the refresh rate of your monitor.

60 refresh 60fps
75 75fps
85 85fps

same think in doom3 but the tearing was real bad in doom3 so vsync on . its not really as bad as problem in halflife 2 i've had v sync off and its not as bad a problem . if you cant stand the tearing turn vsync on. its really up to you !

 

[xiphrex]

The problem with v-sync is that the minute the frame rate drops below your refresh rate, it will drop considerably to get to the next multiple of your refresh rate (in HL2 I am sure this is about HALF your refresh rate). So the higher your refresh rate, the better: i.e. if its 120Hz, game will either be 120 fps, or 60.

If it falls further below 60, then you will notice the fps drop massively. Turn off v-sync and the same intensive part of the game doesnt produce such a noticeable drop in framerate, but yeh you might see some tearing.

As doom3 was an opengl game, for ATI users you could enable tripple buffering which in effect gave you a multiple in between 120 and 60 for example, so instead of going to 60, it would go to something in between, making the effect of v-sync on framerate less severe.

In HL2, I am not sure what it does when v-sync is enabled, but I have found that putting your refresh rate to the max you are allowed at that resolution and limiting your framerate manually in the console until you get minimal tearing is the most effective, as when in graphical intense areas, sure you might get some tearing but I doubt you will notice that in this situation but what you would notice is if you had v-sync on and your framerate suddenly dropped to 30 odd. Just my £0.02.

 

[magictorch]

Hmm, well I tried putting v-sync and it really didn't seem to cause any problems this time, so I'm happy.

Curiously, when the frame rate does drop, it is only by a little, not the expected half.

I give up trying to understand computers, I think I'll just get on playing the game!

 

[Flyingbig]

Some interesting insight in this post, i generally put my refresh to 60hz with vsync on and i find this the best for me. I use a Projector so i keep my reso at 800*600 so thats why i go for 60hz.
So from what you are saying xiphrex would i be wise to run the game at 800*600 and set the refresh to say 100hz? That way minimising the drop in fps? The game will usuually drop down to 35-40 during the open areas even though i reach an average 135fps on the stress test with vysnc off.

 

[xiphrex]

So from what you are saying xiphrex would i be wise to run the game at 800*600 and set the refresh to say 100hz? That way minimising the drop in fps? The game will usuually drop down to 35-40 during the open areas even though i reach an average 135fps on the stress test with vysnc off.

Having read alot about vsync when playing doom3 in various forums etc, I would say, IMO, that you are experiencing what I was refering to.

Try turning off vsync, and then see your frame rate in the exact same open area. I will be surprised if it is not much higher than 35-40.

If you absolutely need vsync on, then I would definately recommend a higher refresh rate, if your monitor/projector allows for it.

 

[Flyingbig]

Thankfully my Projector goes pretty high, haven't tested how high but i have tried 120hz with no problems but picture quality does degrade for some reason compared with 60hz but not enough to not use it if it gave me lass frame drops. I'll test it abit when my projector arrives back from the repair centre which should be on Monday all being well.