The flux of information that a hypothetical system on a cell membrane would have to process in order to dissipate an ionic fluctuation in the solution through a membrane channel is calculated on the basis of nonequilibrium thermodynamics, The developed formula contemplates the relative size and initial relaxation time of the fluctuation, the concentration of the solution, and the size of the ionic channel, It is found that for a wide range of biological concentrations this flux is on the order of 1 Mbit/s for a 10% fluctuation.