why priming time varies in the interval of 16-18ms

[calvin83]

Hi all,
Could anyone enlighten me why I see picture priming time varies from 16ms to 18ms in the output file, instead of being a fixed time of 17ms? I am using a monitor with a refresh rate of 60 Hz. Is this +/- 1ms error?
Thanks~

[jarvis24]

Probably rounding in the report of the display times as opposed to actual variation in times. Although that should typically not show more than 1ms of variation. Could you post a representative log data file that I could look at? Also, what version of DirectRT are you using? i.e., 200x.x.x?