Vsync in games choppy, unstable frame rate

[kam03]

I am experiencing this weird stuttering, pause, lag effect when playing Ridge Racer Unbounded with vsync. So far this is the only tested I have tested.

Fraps has a handy feature that allows you to not only log just the frame rate of an application, but also the timings of individual frames, ie. how long it took to render it. So I started investigating...

Below is a graph of the timings of 60 frames taken from the middle of a 10 second long capture (around 600 frames total).

http://i.imgur.com/BgW7q.png

Notice that it says "Fullscreen" at the top. Here's what happens when i run the game in a window:

http://i.imgur.com/5Wy82.png

So in fullscreen mode you first have one frame that takes a really long time to render, followed by two very fast frames. In windowed mode there's much less variation and most of the frames are around 16 ms long. In theory, if we wanted a perfectly stable 60 frames per second frame rate, each frame would take exactly 16,66 ms to render. But even though the frame rate isn't completely stable in the windowed scenario either, I observed hardly any stuttering. It's so much smoother that I pretty much can't play the game unless I run it windowed.

Any ideas?


Thanks



My specs

Asus P8Z77-V
i7 3770k @ 4.5ghz
Radeon HD 6970 with Catalyst 12.11 drivers
8GB Ram
Windows 7 ultimate 64-bit

[Lowki]

Try using a framelimiter and limit the frames to 59 i know it sounds weird but i swear it works when games act stuttery. Msi afterburner has a built in frame limiter.

[warlord]

use Radeon Pro -> tweaks -> monitor resolution at 59 hz and (dynamic) DVC...it's magic

[naike]

Guys, even if this works I don't think we've solved the actual problem, it's just a workaround.

[kn00tcn]

if ridge racer is the only thing tested... it could be poor implementation of vsync that the game is doing? (or just needing TB to be forced)