Actually i just used Debug.log method in unity to find out the number of eye gaze data points that was recorded during 1 second. But the maximum I received is 30Hz. I ran the program 10 times but everytime it has the same frequency sampling rate. Has my device not been working correctly ? Other than the sampling rate, the 9-point calibration is good. Do i need to try using other tobii eye X device since you said that 40Hz sampling is not normal behaviour.