A question about vsync and framerates

[CarlCAgathon]

I run all my games with vsync enabled. When I have the Fraps FPS counter enabled, the framerate very rapidly switches between 59/60 and occasionally up to 61. Sometimes it stays locked at 60 other times these rapid switches occur.

Is this something that is just inherent to vsync (i.e. inaccuracy in the frame counter) or am I alone in this issue?

Thanks.

 

[MBrown]

Happens to me too in BF3. I just assumed that my FPS was moving that little bit even with vsync on.

 

[Tweak155]

The idea is that it generates enough frames to keep you at 60fps. So 61 suits that and 59 is displayed when it is within a reasonable margin. It's a good way to keep it smooth and balanced.

 

[CarlCAgathon]

Happens to me too in BF3. I just assumed that my FPS was moving that little bit even with vsync on.

Do you notice it in other games too?

 

[cmdrdredd]

Do you notice it in other games too?

I don't use vsync anymore but when I did this was very common to see in my experience.

 

[Pottuvoi]

When getting 59 could mean that single frame took longer than 16ms to render so you got dropped frame.
61 would mean that you got 2 displayed frames within one image, which should be impossible due to the vsync.

Both can be due to an averaging error on counter. (or something similar.)

 

[BrightCandle]

It could be a rounding error, but I think its more likely showing a frame drop. Because of the render input queue that dropped frame quite likely means that at the present call (where fraps measures its time) there really was an additional frame rendered, and the space for that was created by one that was dropped. You kind of see the impact in a funny way because you are measuring the point ahead of the render but actually the additional one just went into the buffer to be rendered. If you take a frame trace with fraps instead you'll see it more clearly as an event with 2 differing blips of time change.

 

[PrincessFrosty]

Vsync locks your frame rate at your monitors refresh rate (60fps @ 60hz) unless your video card can't keep up.

Fraps measures AVERAGE frame rate over time, as such it's slightly prone to rounding errors depending on exactly when you start/stop the time period you average over.

 

[CarlCAgathon]

So bottom line is, it's normal and you guys experience it too? The reason I ask is because there was a 130 page on the Nvidia forums detailing an issue about vsync stuttering with the GTX 6xx series of cards. Apparently it was fixed late last year, but I just want to make sure this behavior with the FPS counter is normal and experienced by everyone.

 

[BrightCandle]

Its normal and experienced by everyone.

 

[skipsneeky2]

So bottom line is, it's normal and you guys experience it too? The reason I ask is because there was a 130 page on the Nvidia forums detailing an issue about vsync stuttering with the GTX 6xx series of cards. Apparently it was fixed late last year, but I just want to make sure this behavior with the FPS counter is normal and experienced by everyone.

My gtx670 must have been something special,cause i was getting stuttering without vsync enabled in BF3 and that was very recent,then when i enabled it sometimes i would get erratic fps drops under 50 in spots where i normally get over 70+ and it was annoying enough just to go back to my 7850 which has none of these problems.

Maybe a unique issue with only my gtx670,putting out a thread about it had some people scratching their heads.

 

[BrightCandle]

My gtx670 must have been something special,cause i was getting stuttering without vsync enabled in BF3 and that was very recent,then when i enabled it sometimes i would get erratic fps drops under 50 in spots where i normally get over 70+ and it was annoying enough just to go back to my 7850 which has none of these problems.

Maybe a unique issue with only my gtx670,putting out a thread about it had some people scratching their heads.

Decidely off topic for this thread. But all means start another one and I'll point you at some resources.

 

[CarlCAgathon]

BrightCandle, one more question. Have you played Far Cry 3 yet? I've heard horror stories about the stuttering present when enabling vysnc. Do you happen to know if this is a game issue not specific to the GTX 6XX series?

 

[skipsneeky2]

Decidely off topic for this thread. But all means start another one and I'll point you at some resources.

Not exactly,i simply mentioned my own experiences with vsync with BF3 with has been mentioned in this thread by a few people.

As for Op,i see 59-61 fps with vsync enabled in some of my games as well but if the gaming experience is smooth,its really nothing to worry about.

 

[VulgarDisplay]

BrightCandle, one more question. Have you played Far Cry 3 yet? I've heard horror stories about the stuttering present when enabling vysnc. Do you happen to know if this is a game issue not specific to the GTX 6XX series?

It's a game issue. AMD and Nvidia both see odd performance in Far Cry 3 at certain framerates and with certain settings.

 

[BrightCandle]

BrightCandle, one more question. Have you played Far Cry 3 yet? I've heard horror stories about the stuttering present when enabling vysnc. Do you happen to know if this is a game issue not specific to the GTX 6XX series?

I do have it but I have been playing ps2 too much to play anything else. My suggestion would be to politely ask if anyone has a far cry 3 fraps trace for a single 680 and a dual 680 and see what you get. Any microstutter movement beyond about 6ms in total top to bottom causes a perceptible problem and jumps that go beyond 33ms are also noticeable one off events. I find one off jumps a lot less problematic actually, they don't affect how well I aim, they just affect that one tiny moment of movement. So focus on the variance in the line more than the individual spikes unless there a lot of spikes.