Apple is now offering the Fusion Drive as a build-to-order option when ordering the most affordable 21.5-inch iMac model, a change in availability from October when the system was limited to high-end versions and the 27-inch iMac.



From Apple Insider:

The revision to the Online Apple Store's build-to-order options, first spotted by French blog MacGeneration and confirmed by AppleInsider, adds Apple's hybrid Fusion Drive as a $250 upgrade to the base model 21.5-inch iMac.

Introduced in October 2011 alongside the redesigned iMac, Apple's Fusion Drive is a hardware and software solution that promises the performance of a solid state drive with the storage capacity of a hard drive. Initial tests showed the hybrid drive to cut startup times in half while increasing read and write speeds significantly when compared to a traditional 5400-rpm hard drive.

  Apple's Fusion Drive now available on new entry-level 21.5" iMac orders