Fearless Engineering: The CS-4 is our first engineering documentary. Through lab footage and conversations with the engineers behind each breakthrough, the film follows the creation of the CS-4, our latest wafer-scale AI system. 0:00 introducing the engineering team 1:09 Wafer-scale history 2:28 Powering the wafer 4:00 The cooling problem 4:18 Designing the cold plate 5:11 Holes in the wafer 6:33 the alignment problem 7:47 The CS-4 PRD 8:35 Designing for deployability and serviceability 11:01 Removing the motherboard 11:25 Removing internal cooling loops 11:41 inventing the power rack 12:35 A one-person lab deployment 14:03 Backpack: 50% fewer components 14:55 Connecting the compute backpack to cooling manifold 17:58 shifting Cerebras’s focus from training to inference 19:09 Building the Cerebras Cloud 20:01 CS-3 vs. CS-4 performance 20:49 3D Stacked DRAM