If you think GPUs are big today, you ain't seen nothing yet. This baby (theoretically) scales all the way up to a 300mm wafer.

Abstract

This paper introduces the Photonic Network-on-Wafer (NoW) GPU architecture to overcome fundamental limitations in electrical interconnect scaling by implementing the inter-GPU network in a wafer- scale optical interposer. We argue that the photonic-NoW GPU is a scalable architecture, delivering significant performance benefits in a power-efficient manner.

Edit: Fixed link to PDF.