I've been wondering why sometimes vsync doesn't always seem to work even when it's specified to be on and I'm running an application full screen. This is something I've noticed on both ATI and NVIDIA in several games even games (not just Rift games) that have an explicit vsync setting and running full screen.
I'll make sure vsync is on the app is full screen (not borderless windowed) and that vsync is set to use application setting or is set to on in my graphics drivers. Yet it's like the graphics card drivers are ignoring the setting and i'll see horrible tearing. This isn't always the case because sometimes vsync does actually work.
Is this known issue? Maybe something to do with Windows 8? Or cloning or extending desktops?