Vertical sync?

[Hawk]

What is it? I see it as an option in most games now does it help framerate? Or what does it do?

 

[choirbass]

well, from what i can tell you, vertical sync limits frame rates to the current onscreen refresh rate... but it also helps eliminate 'tearing' in game play

 

[picture_perfect]

yes the main advantage of v-sync is to eliminate tearing, which are those horizontal lines that run up and down the screen when a scene is moving. the lines actually delineate two different frames from the video card (or two different points in time) which makes the picture look "torn". in some cases this can look just like interlaced video signals or approximate the motion blur seen on LCD screens. to fix it, there should be only one videocard frame per screen refresh; then you get a rock solid picture with no blur or lines. vsync (vertical sync) syncronizes the videocard clock to the refresh rate so that this happens.

there are 2 drawback to vsync that i know of. one, if the video card cant keep up with the refresh rate, fps will drop by whole fractions. for example if the screen refresh is set at 60 hz, and framerate is between 30-59 fps, the maximum fps will be 30 fps (since one refresh is not enough time to render a frame, the card must wait for every other refresh). if you get less than 29 fps the result drops again by half to 15 fps maximum. therefore choppy animation is the rule unless you have a really good videocard that can stay above the refresh rate (hint: set your refresh rate low). if this is not how it works, someone correct me.

the other drawback is debatable and involves the fact that games must slow down to the refresh rate. in other words co-ordinate updates are less frequent and some gamers say it affects their reaction time online. even a 60 hz refresh rate equates to 16ms ping which means it can keep up with most online play. but having said that, there is no doubt more updates are always better. it might make a difference every once in a while when you find yourself dead even if you shoot first.

i use vsync @60hz as long as my card can keep up because the motion quality is so much crisper (a little flicker isnt really bothersome with darker games). older games are ok but with games like doom3 things get too choppy and i turn it off.