Apple's updated their iMac line with fourth generation Intel quad-core processors of the Haswell variety. The enduring all-in-ones also get improved graphics and faster WiFi that's compatible with the 802.11ac standard.
The entry-level 21.5-inch iMac ($1,299 (US)) features a 2.7 GHz quad-core Intel Core i5 processor and new Iris Pro graphics for unprecedented levels of integrated graphics performance. The high-end 21.5-inch model ( $1,499 (US) and both 27-inch models (starting at $1,799 (US)) feature quad-core Intel Core i5 processors up to 3.4 GHz and NVIDIA GeForce 700 series graphics with twice the video memory and up to 40 percent faster performance than the previous generation.
Customers looking for the ultimate in performance can upgrade to quad-core Intel Core i7 processors up to 3.5 GHz and NVIDIA GeForce GTX 780M series graphics with up to 4GB of video memory. All prices are in US dollars.