» Mon May 21, 2012 9:16 pm The iPresentInterval variable causes the game to "smooth" the interval between displayed frames. If you set it to 0, frames will run as fast as possible, making the game appear to run faster and stutter less. But this is 100% guaranteed to cause problems.
The reason problems happen is that Bethesda's games use animation frames as timers. Scripts run every frame, and most events are not timed on the basis of elapsed time but on the basis of elapsed frames. The iPresentInterval variable introduces a delay to make the execution time of each frame appear more consistent, so that frames in which a lot of script code runs take about the same amount of time to run as those in which little or no script code runs.
Setting iPresentInterval to 0 caused similar bugs in Fallout3 and Oblivion. Doing that fixed the "microstutter" problems and made the game appear smoother, but it caused scripted events to go out of synch with animations. The most obvious effect was that dialogue was no longer lip-synched; the longer a NPC spoke, the more out-of-synch their face became with their speech. But more serious problems would eventually occur.
The reason problems happen is that Bethesda's games use animation frames as timers. Scripts run every frame, and most events are not timed on the basis of elapsed time but on the basis of elapsed frames. The iPresentInterval variable introduces a delay to make the execution time of each frame appear more consistent, so that frames in which a lot of script code runs take about the same amount of time to run as those in which little or no script code runs.
Setting iPresentInterval to 0 caused similar bugs in Fallout3 and Oblivion. Doing that fixed the "microstutter" problems and made the game appear smoother, but it caused scripted events to go out of synch with animations. The most obvious effect was that dialogue was no longer lip-synched; the longer a NPC spoke, the more out-of-synch their face became with their speech. But more serious problems would eventually occur.
Which is where FPS cappers came in. FPS Cappers do better what V-Sync was already doing: limiting the frames, only without the issues that come with V-Sync (mouse lag and performance losses being amplified). It doesn't matter with what, so long as you keep the frame-timing at most where Bethesda expected it to be and you don't go over, the game will have no problems. Skyrim already has one. The day-time sync problem has had V-Sync written off as a cause.
Because of that, I would say the info in this thread's title no longer stands. So long as you have an FPS capper in place keeping you at or below 60 FPS, you CAN disable V-Sync without creating any problems for yourself.
EDIT: Interesting that I say that on the post that rolls over the limit....
