Inside the Machine: The AI Back-End Fabric
A modern AI cluster has two networks, and confusing them is a costly mistake. The front-end network connects the data center to the world and looks like ordinary enterprise networking. The back-end fabric connects accelerators to each other and looks like nothing else in computing: it is denser, faster, and more specialized than any general-purpose network. Faraday's read: the back-end fabric is where the fiercest vendor competition and the highest margins now sit, because it is the layer that most directly determines whether a cluster of chips behaves like one computer.
Knowledge check
What is the difference between a cluster's front-end network and its back-end fabric, and why does the back-end fabric receive so much engineering attention?
Show the answer
The front-end network connects the data center to the outside world and to storage, resembling conventional enterprise networking. The back-end fabric connects accelerators directly to one another so they can exchange data during training. The back-end fabric receives intense attention because the speed and consistency of accelerator-to-accelerator communication largely determine how much of the cluster's raw compute is actually usable.