The 12-inch MacBook comes in two variants: a model with a 1.1GHz Intel Core M processor, and another with a 1.2GHz Intel Core M CPU. Both can be upgraded to a 1.3GHz Core M, though, and the prices for that upgrade have been revealed. Continue reading 
Upgraded MacBook with 1.3GHz CPU will run $150 to $250 more than stock models
Upgraded MacBook with 1.3GHz CPU will run $150 to $250 more than stock models
Upgraded MacBook with 1.3GHz CPU will run $150 to $250 more than stock models