A look at V-Sync and all the crap associated with it.

[VIAN]

If you have any questions, no matter how retarded you think they are, post them or pm me about them and I will make changes.

A Frame Buffer is an area in VRAM where the GPU writes a frame and holds it until the monitor is ready to receive it; when it refreshes. The GPU, by default, uses 2 Frame Buffers, alternating between one and the other. With V-Sync enabled, the GPU writes to both buffers, but never overwrites until a Frame Buffer is freed by sending it to the monitor when it refreshes. With V-Sync disabled, the default setting, the GPU writes to both buffers, not caring if it overwrites or not. The GPU can even send out a frame if it?s in the middle of overwriting it, causing artifacts known as tearing. Since the GPU cannot overwrite with V-Sync enabled, it has to wait, meaning it?s wasting power and writing less average frame rate. The GPU doesn?t wait with V-Sync disabled so it writes as fast as possible for optimal performance.

With V-Sync enabled, you will experience jumps in frame rates if your frame rate falls below your monitor?s refresh rate. Say your refresh rate is 60Hz; you will notice jumps from 60fps down to 30fps. A jump like this is very distracting. With V-Sync disabled, you will notice tearing, which is when part of the screen shows part of one frame and the other shows part of another frame. This effect is very easy to see in scenarios where there is flickering light in a game. This effect is more prominent on a LCD than on a CRT but it is noticeably decreased when the average frame rate falls below your monitor?s refresh rate.

Triple Buffering is an attempt to fix the jumps in frame rates that occur with V-Sync enabled by allocating a 3rd buffer in VRAM. It works well, except for a few major details. Not all applications support Triple Buffering in Direct3D. Because Triple Buffering uses 50% more VRAM, you may have to lower your graphics settings in order to free up VRAM for Triple Buffering. It may also introduce mouse lag which may cause a negative gaming experience.

Whether you leave V-Sync enabled or disabled is based on personal preference about which disadvantage you can withstand more. I don?t mind the tearing with V-Sync disabled, especially if my average frame rate is below my monitor?s refresh rate, so I favor V-Sync disabled due to smoother frame rate.

 

[ElFenix]

120Hz? wtf? at that speed the vga signal degradation will lead to fuzziness. sometimes its better to turn down the Hz. you only need 75Hz to eliminate flicker.

 

[KoolHonda]

I find tearing more distracting than the FPS jumps, but to each their own.

 

[VIAN]

Originally posted by: ElFenix
120Hz? wtf? at that speed the vga signal degradation will lead to fuzziness. sometimes its better to turn down the Hz. you only need 75Hz to eliminate flicker.

85Hz, 75 is nonsense. I'm not telling you to enable 120Hz to eliminate flicker am I? the VGA signal will not degrade because it will still be within spec. There may be more inteference if that's what you are saying, but I didn't notice any.

120Hz will have more fps limits, thereby making the jumps smaller, so they are less noticeable.

fps limits for 120Hz:
120, 60, 40, 30, 24

fps limits for 60Hz:
60, 30, 20

If you just don't give a crap about frame rate jumps and tearing is your peeve, then Keep V-Sync on at all times and enjoy.

 

[CP5670]

Vsync without triple buffering is totally useless IMO. The tearing can get annoying, but I would take it any day over the sudden framerate jumps. Not sure about the 120hz though; a sudden 60 to 40 drop isn't that much better than 60 to 30.

 

[VIAN]

Originally posted by: CP5670
Vsync without triple buffering is totally useless IMO. The tearing can get annoying, but I would take it any day over the sudden framerate jumps. Not sure about the 120hz though; a sudden 60 to 40 drop isn't that much better than 60 to 30.

I just thought about that drop, so I removed the section. It's better, but it's not that much better for all the distadvantages of running at 120Hz.

 

[BroadbandGamer]

Originally posted by: VIAN
If you have any questions, no matter how retarded you think they are, post them or pm me about them and I will make changes.

A Frame Buffer is an area in VRAM where the GPU writes a frame and holds it until the monitor is ready to receive it; when it refreshes. The GPU, by default, uses 2 Frame Buffers, alternating between one and the other. With V-Sync enabled, the GPU writes to both buffers, but never overwrites until a Frame Buffer is freed by sending it to the monitor when it refreshes. With V-Sync disabled, the default setting, the GPU writes to both buffers, not caring if it overwrites or not. The GPU can even send out a frame if it?s in the middle of overwriting it, causing artifacts known as tearing. Since the GPU cannot overwrite with V-Sync enabled, it has to wait, meaning it?s wasting power and writing less average frame rate. The GPU doesn?t wait with V-Sync disabled so it writes as fast as possible for optimal performance.

With V-Sync enabled, you will experience jumps in frame rates if your frame rate falls below your monitor?s refresh rate. Say your refresh rate is 60Hz; you will notice jumps from 60fps down to 30fps. A jump like this is very distracting. With V-Sync disabled, you will notice tearing, which is when part of the screen shows part of one frame and the other shows part of another frame. This effect is very easy to see in scenarios where there is flickering light in a game. This effect is more prominent on a LCD than on a CRT but it is noticeably decreased when the average frame rate falls below your monitor?s refresh rate.

Triple Buffering is an attempt to fix the jumps in frame rates that occur with V-Sync enabled by allocating a 3rd buffer in VRAM. It works well, except for a few major details. Not all applications support Triple Buffering in Direct3D. Because Triple Buffering uses 50% more VRAM, you may have to lower your graphics settings in order to free up VRAM for Triple Buffering, or else the GPU will default to Double Buffering. It may also introduce mouse lag which may cause a negative gaming experience. I don't think Triple Buffering is a feature worth thinking about since it is flawed and offers little help towards smoothing out frame rates.

Whether you leave V-Sync enabled or disabled is based on personal preference about which disadvantage you can withstand more. I don't mind the tearing with V-Sync disabled, especially if my average frame rate is below my monitor?s refresh rate, so I favor V-Sync disabled due to smoother frame rate.

So this is why all the XBOX 360 launch games have V-Sync turned off.

 

[Avalon]

I used to use vsync at all times when I had my unlocked Leadtek 6800. Typically I was playing games at 1280x960 @ 85hz, or 10x7 max eye candy @ 100hz, depending on the game. Tearing was unbearable with my 6800, and even with vsync on, I very rarely encountered framerate drops, or ones that were too distracting.

After all, 50fps/42fps is still fairly smooth for most titles, save a few very fast action FPS's.
When I went to a PCI-e system and a took a break from gaming (replaced my 6800 with an unlocked 6200), I found that I only had enough power to play my games at 10x7. At this res, I was using 100hz refresh, and noticed that I could rarely hit a framerate of 100fps, although most of my games play well into the 60s and 70s. Tearing almost didn't exist.

So now I just simply don't enable it any longer.
The only game I still notice it in with my 6200 is in CS:S, but I rarely play that, and when I do, I have more than enough horsepower to play with vsync on.