Opening up the monitor to find a VSync is arguably a kind of lame solution - not very generic so nobody else would have any point reading this anymore. Not to mention I might kill my monitor in the process! There may be another way.

My personal goal for this project was to have 3D movies and gaming on my Samsung Nvidia 3D Vision-compatible screen, hooked up to my AMD graphics-powered rig, with some custom shutterglasses. I have succeeded so far in using AMD's HD3D feature to drive the screen in "3D mode" (a special low-ghosting 120Hz setting) - if you are interested to know how, let me know!

3D gaming is often done using a third-party driver that hooks into the game's render queue and adds a second camera (I use Tridef Iginition). When IZ3D was still around, I used to use their "marked shutter mode", which displays a small square in a corner of the screen. During left-eye frames, the square is black and during right-eye frames the square is white. It allowed me to hook up a phototransistor on this corner to measure the sync straight from the source. Worked great for what it was worth, but the option has disappeared for me now because of using the HD3D mode and IZ3D's quitting business.

So why not re-create this marked shutter mode, allowing me to dig up my old phototransistor setup? I will have a look into AMD HD3D's SDK and see if I can create an app which writes this alternating square to the HD3D quad buffer, overlaying any game Tridef is playing. If it works, it might help out others too!

Stay tuned :)