Review: Apple's Core i3, i5 & i7 iMacs (mid-2010)
Position in the Mac family
The latest iMacs advance Apple's consumer flagship with Intel "Nehalem" Core i3, i5 dual and Quad Core CPUs and Core i7 Quad Core options, dropping the Core 2 Duo CPUs formerly used at the low end of the previous generation of iMacs.
The new processors jump into 3GHz territory, ranging from 3.06 or 3.2GHz Core i3 or 3.6GHz Core i5 options on the 21.5 inch model (each with 4MB of L3 cache), or a 3.2GHz Core i3 or 2.6GHz Core i5 (both with 4MB of L3 cache) or a Quad Core 2.8GHz i5 or Quad Core 2.93GHz Core i7 (both with 8MB of L3 cache) on the 27 inch model.
Previous Core i5 and i7 iMacs were clocked at 2.8GHz or below, but still outpaced the 3.33GHz Core 2 Duo, thanks to the Nehalem QuickPath memory architecture, which includes a direct memory controller on the CPU rather than having the processor talk to RAM via its external chipset. Quad Cores and more onboard CPU cache RAM also speed up the performance of the chips independent of their clock rate.
The new Nehalem microarchitecture also ends Apple's former strategy of using NVIDIA's integrated 9400M across the board to provide its Macs with both standard chipset functions (such as providing a memory controller, SATA, USB, PCIe, audio, and networking functions) and graphics features.
All of the new iMac models offer ATI Radeon HD dedicated graphics processors:
The low end 21.5 inch iMac uses an ATI Radeon HD 4670 with 256MB of GDDR3 memory.
The higher end 21.5 inch iMac uses ATI Radeon HD 5670 with 512MB of GDDR3 memory.
The dual core 27 inch iMac uses an ATI Radeon HD 5670 with 512MB of GDDR3 memory.
The quad core 27 inch iMac uses an ATI Radeon HD 5750 with 1GB of GDDR5 memory.
Comparable Windows PCs often pack on even more graphics RAM. For example, Acer's similarly equipped Gateway One supplies the same ATI Radeon HD 4670 with 1GB of dedicated graphics RAM. This primarily benefits video games, as it allows the game to load texture maps and other data into graphics RAM for optimal performance. Apple's iMacs are designed more to be digital media hubs running iLife and other creative apps, which aren't as hungry for graphics RAM. The company still touts video game play on its iMac systems, but hardcore gamers are not likely to be shopping for Macs given that most games are tied to Windows. However, the iMac's new options for 512MB or 1GB of graphics RAM should help out users who plan to run Windows PC games natively using Boot Camp.
Base models of the iMac ship with 1TB 7200 RPM SATA hard drives and offer an identical 2TB upgrade option (apart from the entry level 21.5 inch model, which ships with a 500GB hard drive). All models also ship with 4GB of RAM, expandable to an officially supported 16GB (8GB on the 21.5 inch models). Prices are unchanged from the previous models, and range from $1199 or $1499 for the 21.5 inch iMac to $1699 or $1999 for the 27 inch model.
CPU upgrades cost a $200 premium, the video card bump costs $150, while the 2TB disk upgrade has dropped from a pricy $250 option to a more reasonable $150. Both models provide four RAM slots, giving users the option to upgrade incrementally without having to throw away RAM to make room for new parts.
The iMac's expansion potential positions it clearly ahead of the compact, entry level Mac mini, which is now easier to access but still offers little potential for serious future upgrades. The Mac Pro continues to deliver even greater upgrade options, with room for 4 hard drives; dual optical drives; two six-core processors; a double-wide, 16-lane PCI Express 2.0 graphics slot and two 4-lane PCI Express 2.0 slots; up to 32GB of installed RAM; and additional Ethernet and FireWire 800 ports. Of course, the Mac Pro is also significantly more expensive even without a display.
On page 2 of 3: The glossy LED-backlit display, keyboard and mouse.
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.
The iMacs present a familiar array of expansion ports:
â¢ Audio out supporting both headphone-style analog output and digital optical mini S/PDIF output. The headphone jack also supports iPhone-style headphones with an integrated mic input and volume and playback control buttons.
â¢ Audio in supporting both line-in analog input and digital optical mini S/PDIF input.
â¢ Four USB 2.0 ports, all of which are available when opting for the default Bluetooth keyboard and mouse.
â¢ One FireWire 800 port.
â¢ Mini DisplayPort with support for VGA, DVI/HDMI, and DisplayPort output as well as DisplayPort input (when using the 27 inch iMac as an external monitor).
â¢ Gigabit Ethernet with auto-negotiation when using crossover cables.
The new iMacs support audio output over the Mini DisplayPort connector, so you can output both audio and video over the same HDMI cable when using the appropriate dongle.
For more information on audio and DisplayPort features, see: Inside the new MacBooks: Audio and Video
For more information on iPhone-style headphone jacks, see: Using iPod & iPhone Video Out: Background and In-Depth Review
On the right side edge, the iMac presents its optical drive slot and a new SD card slot (below), which also works with MMC memory cards, 2.x SDHC cards up to 32GB in capacity, and the newer SDXC (Secure Digital Extended Capacity) cards 32 GB and larger. MiniSD and MicroSD cards require an adapter to use in the slot.
As with recent Mac mini and MacBooks, inserted SD cards stick out far enough to unplug without any physical ejection mechanism, but must be ejected in software prior to pulling them out, just as with any other Mac-mounted disk volume. The slot is only an SD card reader, and does not work with SDIO cards, which provide other features such as WiFi or Bluetooth wireless, GPS, or other features designed for devices with SD expansion-oriented slots.
The new iMacs also include an IR receiver for use with an Apple Remote (not bundled; the new aluminum remote is a $19 option), a built-in iSight camera and microphone, pretty decent built-in speakers, Bluetooth 2.1+EDR and 802.11a/b/g/n wireless networking.
Performance overview: RAM, HD and CPU
The new Macs get massive performance gains from their faster new processors, ranging from 3.06 or 3.2GHz Core i3 or 3.6GHz Core i5 options on the 21.5 inch model (each with 4MB of L3 cache), or a 3.2GHz Core i3 or 2.6GHz Core i5 (both with 4MB of L3 cache) or Quad Core 2.8GHz i5, or Quad Core 2.93GHz Core i7 (both with 8MB of L3 cache) on the 27 inch model.
The iMac's Nehalem chips use Intel's Hyper Threading to virtualize four core performance on two core processors or eight core performance on quad core chips. This technology schedules tasks in such a way to efficiently pack in as much work as possible into the available cores. Essentially, Hyper Threading can enable a two core part to achieve greater performance without actually using any more energy.
At the same time, the CPUs can also do the opposite when there are not multiple threads available to run at the same time, thanks to a feature called Turbo Boost. The chips will effectively shut down idle processor cores and devote its power to the primary, enabling it to increase its clock speed to finish what it has available to do a little faster. This allows the 2.6GHz Core i5 to ramp up to 2.66, 2.8 or 2.93GHz depending on the workload available.
In particular, the new i3, i5 and i7 CPU options excel in floating point math, but the new chips offer significant performance enhancements across the board, leaping up dramatically from the scores of last year's iMac and approaching the high end performance territory of the 2009 Mac Pro. The performance numbers calculated by Primate Lab's Geekbench 2.1 show a much wider span of performance numbers across Apple's current offerings (below). Longer bars are better.
There's also a significant boost from the new iMac's faster new graphics, making the latest models Apple's best option for gamers. While dedicated hardcore video game players are unlikely to be wowed by Apple's iMac specs, the new machines are quite capable of playing modern games at full frame rates. Thanks to the new options available from Valve Software's Steam for Mac, users who enjoy games have the best selection and performance ever available on the Mac OS X platform.
The iMacs all ship with 4GB of 1333MHz DDR3 RAM, up from the previous 1066MHz DDR3 RAM used in the previous generation. Faster RAM helps performance all around, as it allows the CPU to communicate with RAM at that faster bus speed. There are 4 memory slots capable of expanding that up to an officially supported 16GB, or 8GB on the 21.5 inch model, although third parties are marketing 12 or 16GB upgrade kits that can work in either model.
Apart from the entry level model with a 500GB drive, the iMacs all ship with a 1TB 7200 RPM SATA hard drive, which can be upgraded to a 2TB version, and an 8x dual layer DVD SuperDrive. There's also an additional expansion option intended for adding an additional, fast SSD disk to the 27 inch iMac. Since SSD devices are targeted at notebooks, they use a smaller format 2.5 inch mechanism. That means the iMac SSD mounting bay can't be used to hold a secondary full sized, conventional hard drive. Adding an SSD after purchase requires getting a special enclosure cage bracket and custom cabling, which isn't included if you don't opt to buy one as a factory build-to-order option. Third parties are making these custom parts available to their customers, however.
Users who want to upgrade their own conventional hard drive will discover that Apple is now using embedded hard drive temperature sensors to monitor disk heat buildup. This is potentially more accurate and reliable than the previous method of attaching an external sensor on the outside surface of the drive. However, third party hard drive manufacturers haven't agreed on a standard for building temperature sensors into their drives, so users attempting an upgrade will have to find out what drive their iMac shipped with and buy a replacement drive from the same manufacturer.
Apple currently appears to be using hard drives from only two vendors: Western Digital and Seagate. (Note: readers point out Apple is also using Hitachi drives for the 2TB option). System Profiler, which can be launched from the "About this Mac" in the Apple menu, will identify your installed hard drive by serial number, and designates its manufacturer by the first two letters of that number, either WD or ST. Because each vendor supplies a unique thermal sensor connector, upgrading users of late model iMacs will need to buy the same type of hard drive in order to use the same included cable installed inside their iMac. If another drive mechanism is installed, the system will not be able to sense the drive's temperature and will subsequently send the system's fans spinning into overdrive.
The new iMacs in Review
The latest iMacs deliver a significant performance boost and better specs overall. If you're in the market for a new iMac, the new model makes a great, well rounded upgrade. Overall, the new iMacs promise to be a popular addition to Apple's lineup, and deliver a great performance to dollar ratio.
The iMac's glossy screen will not appeal to some users, and some critics have noted that the iMac's ports are all facing the back (making them harder to reach) and that the SD Card slot is too close to the DVD slot, resulting in accidental memory card jams in the optical drive. These complaints seem to be the only perceived flaws in the iMacs' design, indicating a very strong overall package.
Unlike many similarly configured generic PC offerings, the iMac lacks a TV tuner and Blu-Ray player features. There are a variety of low cost third party TV tuners for the Mac, but few options for Blu-Ray movie playback. The best option for Blu-Ray playback is currently Sony's PlayStation 3, although it does not allow iMac users to output video to their fancy new screen without a fairly expensive converter box. Of course, Apple doesn't want to sell users a new HD disc format, it wants people to download its own iTunes videos instead, which don't offer the same kind of high resolution experience.
Rating 4 out of 5
Bright, very high quality screen with (on 27 inch iMac) monitor input feature
Great overall value and reasonably priced upgrade options
Fast new performance options for CPU and GPU, faster RAM and bus speeds
Higher capacity SDXC card slot is a handy convenience
Audio-integrated support for Mini DisplayPort, HDMI output
No PC-style TV/Blu-Ray convergence features
HDMI output requires a converter dongle
Where to Buy