OPTICAL AND ELECTRICAL COMPUTING ENERGY USE COMPARISON

Optical computing has been proposed as a replacement for electrical computing to reduce energy use of math intensive programmable applications like machine learning. Objective energy use comparison requires that data transfer is separated from computing and made constant, with only computing variable. Three operations compared in this manner are multiplication, addition and inner product. For each, it is found that energy use is dominated by data transfer, and that computing energy use is a small fraction of the total. Switching to optical from electrical programmable computing does not reduce energy use.