NvAPI_GetVBlankCounter takes a long time

Hi,

I’m using NvAPI_GetVBlankCounter to synchronize a distributed simulation to my displays.
The problem I’m encountering is that this function seems to use a critical section and it takes an unpredictable amount of time to return this number.
Sometimes this function takes up to 2ms to return.

Is this correct behaviour or am I using this function wrong?

Regards,
Andreas