SAN FRANCISCO (Reuters) -Apple on Monday introduced new MacBook Pro and iMac computers and three new chips to power them, with the company saying it had redesigned its graphics processing units (GPU), a key part of the chip where Nvidia dominates the market. In the U.S., the 14-inch MacBook Pro laptop will start at $1,599 and a 16-inch version starts at $2,499. Apple has seen a revitalization in its Mac business, roughly doubling its market share to nearly 11% since 2020 when it parted ways with Intel and started using its own custom-designed chips as the brains of the machines, according to...