Tesla Inc. TSLA, +1.95% revealed in its earnings conference call Wednesday that it has developed its own hardware to handle self-driving features in its cars. Tesla had been relying on hardware from Nvidia Corp. NVDA, +1.85% , but Chief Executive Elon Musk said Wednesday that he wanted to move away from the GPUs Nvidia offers. "I'm a big fan of Nvidia, they do great stuff, but ... the transfer between the GPU and CPU ends up being what constrains the system," Musk said in announcing the new chips, which he said had been in development for more than two years. "Probably time to let the cat out of the bag, because that cat's going to come out of the bag anyway," Musk said. Nvidia Chief Executive Jensen Huangtold MarketWatch in May that Tesla's business was not a material concern as the Model 3 rollout faced delays. "The volume from Tesla is not that high, there is no material difference one way or the other," Huang said then. Nvidia shares dipped about 0.3% after the announcement was made, while Tesla shares were trading 10% higher in after-hours trading.