A method for performance data transmission control executed by one or more processors includes receiving performance data associated with output timings, the performance data including continuously varying operation data whose value changes continuously; detecting characteristic points of change from the continuously varying operation data; thinning out the continuously varying operation data other than the characteristic points of the change; and generating unit performance data to be transmitted to an external device, based on the performance data in which the characteristic points in the continuously varying operation data have been detected and in which the continuously varying operation data other than the characteristic points have been thinned out.