Review: Apple's Core i3, i5 & i7 iMacs (mid-2010)
The most obvious feature of the iMac is its massive screen as large as 27 inch and delivering nearly the resolution (2560x1440) of the 30 inch Cinema Display HD (2560x1600). That's currently the largest display available from any all-in-one PC vendor, and nearly equivalent to four 13.3 inch MacBook screens (1280x800) in a single panel. The new iMac is still priced just $100 less than Apple's standalone 30 inch big screen display, despite packing in a powerful computer and new LED backlighting.
The 27 inch iMac, along with its smaller 21.5 inch partner, sport high quality IPS LCD screen technology, resulting in spectacular color, contrast and wide viewing angles. Like previous models, the glossy screen is covered with a glass panel that extends across the entire top face of the unit. The screens are also LED backlit (unlike the now discontinued 30 inch Cinema Display HD), which means they turn on instantly and allow for finer grained control over brightness than conventional cold cathode fluorescent lamp backlighting. LED backlighting is also environmentally friendly because it uses no toxic mercury. Overall, the new machines also meet Energy Star 5.0 and EPEAT Gold standards for energy efficiency and environmentally-sound design, manufacturing, and use of recyclable materials.
Both iMacs support video output up to 2560x1600, capable of driving a 30 inch Cinema Display HD. The Mini DisplayPort supports VGA, DVI/HDMI and DisplayPort screens, but requires an inexpensive dongle to support VGA, DVI, or HDMI cables. The 27 inch iMac is also able to act as a display for another DisplayPort computer (or a 720p HDMI device, if you use a relatively expensive $150 HDMI to DisplayPort signal converter). It is the first and currently the only Mac to support this new capability. The 21.5 inch iMac doesn't support video input.
Because the new 27 inch iMac is now priced less than the aging 30 inch Cinema Display HD with a similar resolution, it makes sense for users who need a big external screen to buy it instead and gain a free rendering machine capable of running Xgrid or Qmaster distributed processing tasks in the background as a free bonus. When connected to a DisplayPort output device, the iMac's screen can be switched between the internal computer and the external video source. Currently, this only allows the new iMac to serve as a display for late-modeled Macs and other PCs capable of DisplayPort output, unless you also buy an HDMI to DisplayPort signal converter.
Wireless Apple Keyboard, Magic Mouse, Magic Trackpad options
The new iMacs now come standard with a Bluetooth Wireless Keyboard and multitouch Magic Mouse. These can be traded for a compact or full sized (with numeric keypad) USB keyboard and/or a standard USB Apple Mouse (the same model that was formerly referred to as Mighty Mouse). The new Magic Trackpad is available as a $69 option, but there's no way to upgrade from the mouse at a reduced cost. Apple suggests users may want to use both.
Apple's Bluetooth keyboard is virtually identical to the MacBook's built-in keyboard, and is slightly modified from Apple's original 2007 Bluetooth keyboard in that it now only uses two AA batteries and has moved the wireless receiver to the center of the back panel. Users on a desktop system might want to opt for the full size USB keyboard instead, as Apple's unframed Bluetooth keyboard almost seems too small; while the key spacing is no different than Apple's popular MacBooks, the tiny keyboard feels undersized in relation to the vast screen. Why not have a numeric keypad and the extra function keys if you have the desk space for it anyway?
Typing on the super low profile keyboard feels as comfortable as a MacBook; attempts to try using a conventional keyboard with a deeper physical key movement now feels clumsy. The actual typing experience between the wireless and USB keyboards shouldn't be any different; the only real difference is the availability of additional keys. Interestingly, Apple now offers a small keyboard without the extra keys in a wired version. All keyboard and mouse options are priced identically.
The new Magic Mouse was reviewed earlier. All Magic Mouse interactions with the new iMac, which ships with the driver software ready to go, felt natural and worked without issues. While setup and use of the new Magic Mouse seemed flawless, the Bluetooth keyboard also seemed to lose its connection too often, although this may have been related to our test environment, which has multiple Bluetooth and WiFi devices all contending for use of the same bandwidth. Apple provides some additional information on environment issues that can impact wireless performance.
It's nice to have the wireless options provided at no extra cost however, and users who decide they don't like the Bluetooth keyboard won't face much expense in buying their own third party keyboard to fit their own particular preferences. Users who plan to run Windows XP/Vista/7 on their iMac natively using Boot Camp must install an update for Windows, which handles the wireless devices differently than Mac OS X does. An Apple support document explains more about this.
On page 3 of 3: Expansion ports, performance overview.