Apple announced a processor upgrade for its laptops that replaces the Intel Core Duo processor with the faster Core 2 Duo processor. Apple claims that the processor change provides the new MacBooks with up to 25 percent greater performance than their predecessors (see " ," 2006-05-22). The same three models are still available: a white 1.83 GHz MacBook for $1,100, and differently configured 2.0 GHz models in white ($1,300) and black ($1,500). The other changes - only in the 2.0 GHz models - are a doubling of the default RAM configuration to 1 GB and the addition of a double-layer SuperDrive. It's also now possible to order a MacBook with up to 200 GB of hard disk storage, though the 200 GB drive is a slower 4200 RPM drive, whereas all the other drives spin at 5400 RPM. The new MacBooks are available immediately.