Summary

According to the Financial Times, citing Doug Lefever, the chief executive of Advantest, it takes three to four times longer to test Blackwell data center GPUs than Hopper data center GPUs because each unit has to be tested dozens of times on different tools before shipping.

Typically, as the transistor count grows, test complexity grows almost exponentially, as chips require more test patterns and longer test times. Test protocols must cover high-speed interconnects, stress conditions, thermal conditions (which, in the case of the B200, are extreme), and multiple operational modes (Blackwell adds FP4 support).

There’s more to this. TSMC’s CoWoS-L 2.5D packaging techniques introduce additional test steps (and sometimes multiple test phases) to ensure that each component in the package is functioning correctly and that interconnects are reliable.