Hi @Daniel_Y and @Corvus I have several queries and findings : 1. In vive developer page I found that, refresh rate for headset and for eyetracking output frequency are different. For headset it is 90 hz and for eyetracking output frequency its 120 hz. https://developer.vive.com/resources/knowledgebase/vive-pro-eye-specs-user-guide/ 2. I am getting different refresh rate for headset on different monitor. I tested on two monitors, one is Asus ROG(default monitor fps:144hz), another one is DELL(default monitor fps:60hz). From Asus ROG I have got 90 HZ frame rate for headset but from Dell monitor I am getting less than 60 hz. I wonder what relationship between monitor refresh rate and headset refresh rate is. Can you explain? I have calculated refresh rate using the following code: https://paste.ubuntu.com/p/YYHqbpnPNC/ 3. Can you suggest or give example code how I can measure refresh rate for headset and eye tracking output frequency? 4. The last thing is: “Gaze data output frequency (binocular):120Hz” , to my understanding this means, we can collect 120 data points per second, right ? is there any dependency between Headset refresh rate and eye tracking output frequency?