The newest top-of the line iMac (Apple iMac 27-inch)

The Apple iMac 27-inch (Thunderbolt)  is the newest top-of-the-line iMac, and it adds second-generation Intel Core i processors (aka, Sandy Bridge) to Apple's class-leading all in one Mac desktops, along with Thunderbolt ports first seen on the new MacBook Pro laptops. It has that huge, beautiful high-resolution screen, killer (if aging) design, and it is fast, fast, fast. Your "Mac OS or die" art director already wants one. Still, it's not enough to unseat the HP TouchSmart 610-1065qd as our high-end all in one desktop Editor's Choice, given that the latter offers quad-core power, a touch-screen display, and an innovative screen reclining feature, all for about $200 less.

Design
On the outside, the iMac 27-inch (Thunderbolt) looks just like its aluminum and glass predecessors. It has the same huge 27-inch 2,560-by-1,440 resolution display, which is formatted with a 16:9 aspect ratio and is higher resolution than the 1,920 by 1,080 required for true 1080p HD. The display is so bright that Apple added a new ambient light sensor to auto-dim the screen, so users in brightly lit studios can keep their eyes from straining when a cloud obscures the sun or if someone draws the drapes over the window. The glass panel protecting the LED-backlit LCD display is glossy, one of the few nits against the iMac 27-inch (Thunderbolt). I'd like to see a matte finish option for graphics professionals who want it. Speaking of graphics professionals, Apple color calibrates each display before shipping it to the final user. Color calibration won't necessarily be a big consideration for the average consumer, but it's a boon to the graphics artist who makes her living with the iMac.

The desktop comes with a 1TB, 7,200rpm internal hard drive, though well-off speed demons can also add an optional 256GB SSD for an additional $600. Combinations, including a single 256GB SSD (by itself) and/or 2TB hard drive upgrade, are available on Apple's website. The system comes with Apple's wireless keyboard and your choice of either Apple's Magic Mouse (which our review unit came with) or Magic TrackPad (which used to be a $60 option). I personally like the TrackPad, since it has more multi-touch functions than the mouse. The 27-inch iMacs come with 4GB of memory standard, and support up to 16GB maximum. Like previous iMacs, the system memory is the only easy-to-access internal upgrade you can do on the iMac 27-inch (Thunderbolt): further internal expansion requires specialized tools, familiarity with electronic repair techniques, and much intestinal fortitude. Most users will upgrade their system via external ports.

Features
The iMac 27-inch (Thunderbolt) comes with four USB 2.0 ports, one FireWire 800 port, audio in/out, Gigabit Ethernet, a SDXC card slot, and—new for 2011—two Thunderbolt ports. Thunderbolt is the currently shipping implementation of Intel's "Light Peak" interconnect, which uses the same shaped plug as mini DisplayPort, though the Thunderbolt connector is capable of so much more than simple display support. You could, in the future, connect many different peripherals to the Thunderbolt port, like hard drives, Fiber Channel SAN arrays, video interfaces, and adapter cables for HDMI, DVI, etc. But for the time being, you can only use the Thunderbolt port for video: You can connect one of the newer MacBook Pro laptops with Thunderbolt and use the iMac as an external monitor. Or you can use the two Thunderbolt ports to connect up to two external mini DisplayPort monitors so you can extend your workspace on three monitors (including the internal display).

Thunderbolt is theoretically capable of 10 Gbps bi-directional throughput, so you can support multiple peripherals per port, which is twice the speed of USB 3.0. Thunderbolt can be daisy chained, so the same two ports on the iMac 27-inch (Thunderbolt) can, for example, support dual displays and multiple external hard drives simultaneously. Hard drive and peripheral manufacturers like LaCie, Promise Technology, and BlackMagic have announced other peripherals for Thunderbolt, but you'll have to wait at least until Summer 2011 for those. Apple has reportedly come out saying (via Macworld) that you need a Thunderbolt-equipped Mac desktop or laptop to use the iMac as an external monitor: older mini DisplayPort equipped Macs (like the Mac mini and older MacBooks) won't be able to use the new iMac as an external display. Though this won't affect too many users at this point, it does count as a nit against the new technology. More annoying is the fact that the new iMac needs new (as yet unreleased) Thunderbolt-to-HDMI input adapters if you want to plug in a HDMI (or DVI or DisplayPort) device like a DVR or another PC. This is one case where other all-in-one desktops like the Editor's Choice HP TouchSmart 610-1065qd ($1,789.99 list, 5 stars) (with its two HDMI inputs) outshines the iMac 27-inch (Thunderbolt).

Another nit is Apple's shunning of Blu-ray technology. Internal Blu-ray drives are not an option on any iMac. Apple doesn't view Blu-ray optical discs as a replacement for data DVDs, and would rather you bought your HD videos from the iTunes Store rather than on Blu-ray. Blu-ray won the High-Definition wars long ago, especially for movie buffs, so that omission is still puzzling.