The refreshed machines include dual core processors from 3.06 GHz up to 3.6 GHz, and quad core processors from 2.8 GHz up to 2.93 GHz. Hard drives go up to 2TB and the iMac also supports a drool-worthy 256 GB solid state drive option. Standard RAM includes 4GB of 1333 MHz DDR3 SDRAM with four SO-DIMM slots, allowing up to 16GB. The 21.5" model maxes out with a 3.6GHz Core i5 chip, and the 27" tops out with a 2.93GHz quad-core i7 chip.
Graphic options on the new machines include the ATI Radeon HD 5750. The new machines add support for the SDXC memory card format as well. The 27-inch model also supports dual hard drives as a BTO option.
Apple's press release covers the new models' speedy goodness.