@DuaneDibbley The response rate of optical sensors is easy to test with a polling rate tester such as MouseMovementRecorder.exe which I linked to a few post ago.
Set the mouse dpi to 800dpi or even 3,000dpi. Move the mouse very slowly and MouseMovementRecorder.exe will show the optical sensor replying at a very low frequency. Better yet, take your hand off the mouse so it's not moving and the optical sensor will reply at 0Hz. If the optical sensor is replying at 0Hz with a 1,000Hz bInterval, that means the optical sensor is NAKing 1,000 poll requests.
Now increase the dpi to 20,000 and see what MouseMovementRecorder.exe reports even with the mouse completely stationary. It'll be replying at a much higher frequency.
Also of interest, Windows polls the mouse buttons on the Viper 8k at 8,000Hz but only polls the optical sensor at the polling rate set in the Razer mouse software. The polling rate for optical sensor is rate limited with NAKs.
If Windows is polling the mouse at 8,000Hz but the optical sensor is set to 1,000Hz, then the sensor NAKs 7,000 out of 8,000 poll requests. If the mouse is completely stationary at low dpi, it's NAKing all 8,000 polling requests.