Feature enhancement in latest git:
This was previously hard coded in but is now disabled by default.
This feature when enabled draws mouse updates to the front buffer instead of waiting for full frame updates from the guest in an attempt to achieve better mouse input synchronization with the hardware cursor on the physical GPU. However on some hardware pipelines the excessive calls to
glFlush causes a GPU pipeline stall and the mouse can become “jumpy”.
The down side to this is the current frame will be re-drawn on every mouse movement even if there was not a new frame from the guest, this will mean that the frame sync with the guest can be lost and there is a higher chance of frames being dropped. To avoid dropping frames you can turn vsync off at the side effect of screen tearing, it is up to you.
To turn this back on use the command line option below appropriate depending on the renderer you are using:
-o opengl:splitmouse=1 or
If you are primarily playing games or using applications that use a software, no mouse, or a rendered mouse, and the windows desktop experience doesn’t worry you too much this feature should be enabled for best performance if you wish to retain frame sync with the guest.
You can evaluate the effects of this feature by using the MPRT test (Avoid this test if you are prone to epilepsy) while moving the cursor around.