Apple may have a faster, unannounced MacBook for Friday's launch

A more powerful, but unannounced, 12-inch MacBook is coming to Apple's lineup this Friday, but the build-to-order configuration will cost at least a $250 (£170, AU$325) premium over the base model.

In addition to the announced 1.1GHz dual-core Intel Core M processor with 256GB storage in the base configuration and the 1.2GHz dual-core Intel Core M processor in an upgraded build with a 512GB solid state drive, Apple will have a build-to-order option with a faster 1.3GHz processor and a 256GB drive. The unannounced configuration is expected to cost $1,549 (£1,040, AU$2,015), a $250 (£170, AU$325) premium over the $1,299 (£875, AU$1,690) base unit.

Apple will also have an even higher build-to-order configuration with more storage. Priced at $1,749 (£1,175, AU$2,275), that configuration will come with a dual-core 1.3GHz processor and 512GB of storage. All models will come with 8GB RAM and integrated an Intel HD Graphics 5300 processor.

The pricing and configurations were initially reported by MacRumors based on information that was published by Apple hardware reseller partner Expercom. Apple's website does not list either 1.3GHz option.

The 12-inch MacBook will become available Friday, April 10 at Apple alongside pre-orders for the Apple Watch.

USB-C

Apple made headlines when it debuted the MacBook as the unit comes with a single USB-C port that handles input, output, video-out, and charging. Given the new port, which accepts a new reversible connector tip, existing accessories will not work without an adapter. Power users will likely need to use an adapter or multiport hub to connect multiple accessories, or even to have a USB flash drive attached while trying to charge the MacBook's battery.

Since the MacBook's release, rival Google also announced an update to its Chromebook Pixel. The new Pixel comes with two USB-C ports along with support for legacy USB ports, making it feel less constrained than the new MacBook.

Given its screen size and slim form factor, the MacBook will compete with Windows hybrids and Ultrabooks, including Microsoft's Surface 3 and Surface Pro 3.