Advanced Micro Devices Inc. started selling new personal-computer chips that challenge market leader Intel Corp. for the first time in years.

The three chips in AMD’s Ryzen line, which became available in high volume on Thursday, represent the first major processor redesign in five years for the Sunyvale, Calif., company, which long has been a distant second in supplying PC chips. The new chips roughly double the performance of its previous products and approach or exceed that of comparable Intel units, according to independent...