Veritcal Sync... what is it?

dlb · Apr 20, 2009

I've been noticing that many of the newer games (Crysis, BioShock, STALKER) have a setting under 'Video Options' for 'Vertical Sync' or sometimes abbreviated to 'VSync'. What the heck is 'VSync'? I haven't messed with it so I have no idea what effect it may (or may not) have on gaming....
:-D

Thanks!

DavidGP · Apr 20, 2009

Hi dlb

from memory its the games or graphics card setting to allow you to match or not allow it to go above the monitors default refresh rate, if the image data is sent too quickly and the monitors refresh rate cannot keep up the cause of tearing is seen in a game.

TBH, thought these days of LCDs its not needed and can be disabled, was more a CRT issue, dont quote me on this as cannot remember.

Old article and may highlight what you need to know http://www.d-silence.com/feature.php?id=255 not fully read it, so if it contradicts my above... ooops!

dlb · Apr 20, 2009

Thanks Halo... I haven't checked out the link you provided, but I have read online where some folks noticed significant drops in performance when VSync was enabled in these higher end games. I have also read in some user comments on video cards (primarily at Newegg) where they said "I can turn up everything to high, and even enable VSync!" when referring to how great a card's performance is. I have no idea if these people were using CRTs or LCDs. Perhaps I should just try enabling in and see what happens!

(BTW- I have a 21" wide screen LCD and just acquired a brand new nVidia GTX260 :celebrate )

dlb · Apr 20, 2009

OK- I just read something VERY INTERESTING at the link Halo provided above:

In order to get a smoother transition between frames in 3D games, the video card puts the contents of the upcoming frame into its frame buffer. [The frame buffer is part of the local memory that resides on the video card itself] It then moves the contents of the frame buffer to the screen. When this is complete, the frame buffer gets the next frame. This process repeats its self over and over.

Now, what is VSYNC? Well, VSYNC is basically the synchronizing of buffer swaps with your monitor's refresh rate. With VSYNC enabled, frame rates will not exceed the monitor's current refresh rate for that particular resolution. For example, if your monitor is using a refresh rate of 85Hz at 800x600, with VSYNC enabled, you will theoretically never exceed 85fps. So the refresh rate creates an artificial barrier that limits the frame rate.

So what happens if you are playing on an older monitor that only supports a 60Hz refresh rate. Will you have to live with a maximum of 60fps (assuming that your system can generate more fps)? Not necessarily. Newer video cards give you the option of disabling VSYNC. What happens is that this allows the buffer swapping to occur without synchronizing with the monitor's refresh rate.
Click to expand...

There is much, MUCH, MUCH more information on this at the link above, but this is a really good summary of what I was after.

THANKS HALO!!!! :highfive

[dlb]

(. . . and, yes, the article is quite old, like 9 years or so :-o but I think it still applies )

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Veritcal Sync... what is it?

dlb MajorGeek

DavidGP MajorGeeks Forum Administrator - Grand Pooh-Bah Staff Member

dlb MajorGeek

dlb MajorGeek