Jen-Hsun Huang has reinvented his graphics chip firm Nvidia three times now. He founded the company in 1993 to take 3D graphics from Silicon Graphics supercomputers to ordinary PCs. The company beat out scores of rivals by pumping 3D graphics chips out every six months on a relentless cadence. Now it is the last major stand-alone graphics makers, squaring off against microprocessor vendors Intel and Advanced Micro Devices. Nvidia remains one of the innovation leaders of Silicon Valley, and recent events have shown that it never pays to second guess the wisdom of Huang and his merry band of cohorts.