Fusion Drive comes to low-end 21.5-inch iMac for $250 extra

Buyers eyeing the most "frugal" version of Apple's new iMac will now be able to add a 1TB Fusion Drive as a build-to-order option (hat tip to MacRumors). The drive, which combines a solid-state disk and spinning hard drive into a single volume, was previously available only on the 27-inch iMac and the higher-end 21.5-inch version, with the low-end 21.5-inch iMac being left out of the fun. Less than two months after the 21.5-inch iMac's launch, however, Apple has now added in the Fusion Drive for an extra $250.

Fusion Drive was announced last October during Apple's media event, in which it introduced the iPad mini and the redesigned iMacs. Apple advertises Fusion Drive as faster and more efficient than a spinning drive—it stores slow, common tasks (booting, app loading) on the SSD side while storing less frequently used items on the hard drive. For more in-depth information on Fusion Drive, Ars Technica's Lee Hutchinson has done plenty of analysis on how the tech works and even how to roll your own system.