Summary: "Video synchronization method" Default: auto Example: finish-sleep-swap-finish Type: choice

Choose the method used to ensure video synchronization with the display. Valid values are:

Value: auto (Auto) Automaically choose sync method based on platform. Value: swap (Swap) Most basic method, but will probably not mantain emulation perfectly in sync on many GPUs due to pipelining and the swap buffers command returning before it is completed. Value: swap-finish (Swap-Finish) This method should force the emulation to be in sync with the display, but glFinish may use a busy-loop and cause high CPU usage. Value: finish-swap-finish (Finish-Swap-Finish) Execute a glFinish also before swapping buffers. May work better with some OpenGL drivers. Otherwise same as swap-finish (High CPU usage with many drivers). Value: finish-sleep-swap-finish (Finish-Sleep-Swap-Finish) Same as above, but sleep before executing the swap command. The sleep time is based on the (estimated) time left to the next vblank. This should reduce the CPU usage a lot, but on some systems/drivers, the display will not be synchronized properly. Value: sleep-swap-finish (Sleep-Swap-Finish) Same as above, but do not issue a glFinish before starting the sleep. This should use less CPU than the above option, but some drivers seem to need the finish before the sleep to achieve proper sync. Value: swap-fence (Swap-Fence) Set a fence after swapping buffers and poll periodically (with sleeps) for completion of swap. This seems to work very well on Linux with recent nVIDIA drivers. Value: swap-sleep-fence (Swap-Sleep-Fence) Same as above, but sleep a while (based on estimated time to next vblank) before starting to poll the fence, (in case the test-fence method blocks with high CPU usage, problem seen on nVIDIA/Windows).

The default value is:

• finish-sleep-swap-finish - for Windows and Mac OS X
• finish-swap-finish - for Linux.

See also [video_sync].