The basic logic of yield
Yield is the fraction of manufactured chips that become usable products. Defect density, die area, process window, and design redundancy shape yield together. A large GPU die has a higher chance of encountering random defects, so it depends heavily on mature process control, redundancy, and careful design margins.
The test chain
Wafer sort identifies candidate known-good-die before expensive packaging. After packaging, products still need functional test, speed test, memory-link test, power test, burn-in, and temperature screening. In a GPU plus HBM module, a failure in one die or one link can affect the entire assembly.
Why binning matters
Binning sorts chips by frequency, voltage, power, enabled-unit count, and stability. Some GPUs can disable defective or marginal compute units and ship at a lower specification. Binning recovers borderline silicon and lets a product line cover different power and price points.