Not sure, but I think he meant to say a week old developer version?
I have/had the same exact issue. I run all my games in fullscreen with the frame rate counter enabled and noticed periodic frame lagging in an interval much like the OP describes. For me, it occurs more frequently with the OpenGL backend than the D3D one, and it occurs less frequently on the D3D backend when the game is already running at a consistent framerate of 60 (my monitor's refresh rate). The microstuttering is a lot more noticeable on both backends if the native framerate of the game is 30. When this occurs, there is definitely a noticeable stuttering even though the frame rate counter never budges. The 'microstuttering' caused by the Shader Cache I believe causes the frame rate counter to change which isn't what the OP is saying. If it's what I'm thinking of, the shader cache causes more of a 'hitch' in the frame that results in a momentary pause during game play.
I've had this problem for a long time, and I believe part of the issue is caused by the Desktop Windows Manager (more specifically, Desktop Composition with the Aero theme). Desktop Composition applies its own vsync to eliminate screen tearing on your windows. Even if vsync is disabled in either one of Dolphin's backend settings, you'll notice that screen tearing is still eliminated. I also noticed that along with stuttering, this seems to cause some input lag as well. While disabling Desktop Composition will bring back a lot of screen tearing if your game is running below your monitor's refresh rate, the microstuttering should be gone.
Unfortunately since you're using Windows 8.1, I've heard that they made disabling Desktop Composition very difficult. If you were using Windows 7 you could either disable the feature manually or switch to the Classic theme (which disables pretty much every window effect). Switching to the Classic theme in Windows 8 still uses Desktop Composition as far as I know. You can still disable Desktop Composition completely in Windows 8.1, but I wouldn't recommend it since it seems to break a lot of Windows features. I believe Windows is supposed to disable Desktop Composition automatically when running something in fullscreen, but that doesn't happen with Dolphin since I believe Dolphin isn't using exclusive fullscreen (aren't both Dolphin and PCSX2 currently using borderless fullscreen?).
Although I could be wrong on all my assumptions, but I thought I'd post them here since you have pretty much the same exact problem as I have.
I'm also not sure if the backend vsync setting is still working under Windows. Can anyone confirm this? I remember trying it out while Desktop Composition was disabled and it didn't eliminate the screen tearing. Could be the intended effect though...
I have/had the same exact issue. I run all my games in fullscreen with the frame rate counter enabled and noticed periodic frame lagging in an interval much like the OP describes. For me, it occurs more frequently with the OpenGL backend than the D3D one, and it occurs less frequently on the D3D backend when the game is already running at a consistent framerate of 60 (my monitor's refresh rate). The microstuttering is a lot more noticeable on both backends if the native framerate of the game is 30. When this occurs, there is definitely a noticeable stuttering even though the frame rate counter never budges. The 'microstuttering' caused by the Shader Cache I believe causes the frame rate counter to change which isn't what the OP is saying. If it's what I'm thinking of, the shader cache causes more of a 'hitch' in the frame that results in a momentary pause during game play.
I've had this problem for a long time, and I believe part of the issue is caused by the Desktop Windows Manager (more specifically, Desktop Composition with the Aero theme). Desktop Composition applies its own vsync to eliminate screen tearing on your windows. Even if vsync is disabled in either one of Dolphin's backend settings, you'll notice that screen tearing is still eliminated. I also noticed that along with stuttering, this seems to cause some input lag as well. While disabling Desktop Composition will bring back a lot of screen tearing if your game is running below your monitor's refresh rate, the microstuttering should be gone.
Unfortunately since you're using Windows 8.1, I've heard that they made disabling Desktop Composition very difficult. If you were using Windows 7 you could either disable the feature manually or switch to the Classic theme (which disables pretty much every window effect). Switching to the Classic theme in Windows 8 still uses Desktop Composition as far as I know. You can still disable Desktop Composition completely in Windows 8.1, but I wouldn't recommend it since it seems to break a lot of Windows features. I believe Windows is supposed to disable Desktop Composition automatically when running something in fullscreen, but that doesn't happen with Dolphin since I believe Dolphin isn't using exclusive fullscreen (aren't both Dolphin and PCSX2 currently using borderless fullscreen?).
Although I could be wrong on all my assumptions, but I thought I'd post them here since you have pretty much the same exact problem as I have.
I'm also not sure if the backend vsync setting is still working under Windows. Can anyone confirm this? I remember trying it out while Desktop Composition was disabled and it didn't eliminate the screen tearing. Could be the intended effect though...