How do the "Mid-2011" Aluminum iMac models compare to the "Mid-2010" models that preceded them?

The "Mid-2011" Aluminum iMac models -- the iMac "Core i5" 2.5 21.5-Inch, "Core i5" 2.7 21.5-Inch, "Core i5" 2.7 27-Inch and "Core i5" 3.1 27-Inch -- look identical to the "Mid-2010" models they replaced -- the iMac "Core i3" 3.06 21.5-Inch, "Core i3" 3.2 21.5-Inch, "Core i3" 3.2 27-Inch and "Core i5" 2.8 27-Inch -- because both lines use the same "edge-to-edge" glass design and a "seamless all aluminum enclosure" with the entire computer tucked discreetly behind a 21.5" or 27" glossy flat-panel display.

Photo Credit: Apple, Inc. (21.5" - Left, 27" - Right)

External Differences

The displays used in both the "Mid-2011" and "Mid-2010" models are the same 8-bit 16:9 LED-backlit TFT Active Matrix LCDs. Both use IPS (In-Plane Switching) technology, which provides more accurate color than earlier technologies even at wider viewing angles (178 degrees both horizontal and vertical). All of these models also have speakers mounted under the display and an integrated webcam -- although the "Mid-2011" has a higher-resolution "FaceTime HD" webcam compared to an "iSight" webcam on the earlier line. The "FaceTime HD" webcam also reportedly has a wider viewable angle, and as first discovered by MacGeneration, an ambient light sensor to the left of the camera lens as well.

By default, "Mid-2010" iMac models came with a compact aluminum wireless keyboard sans numeric keypad and a wireless "Magic Mouse," where the "entire top is a seamless multi-touch surface" that allows one to "navigate using intuitive finger gestures." As an optional US$69 upgrade, the "Mid-2010" models also could be configured with a then new a "Magic Trackpad" that provides multi-touch input like on a recent Apple notebook. For the "Mid-2011" iMac line, Apple continues to ship the same keyboard by default but gives the user the option of either the "Magic Mouse" or the "Magic Trackpad" at no extra charge.

Connectivity Differences

Apart from two signficant exceptions, connectivity between the lines is the same. All have four USB 2.0 ports, a Firewire "800" port, Bluetooth 2.1+EDR, Gigabit Ethernet, an SDXC SD Card slot, and audio line in and out ports. Both lines have built-in AirPort Extreme (802.11a/b/g/n) that officially is the same, but as first determined by the now defunct HardMac, the "Mid-2011" models unofficially support faster 450 Mbit/sec "MIMO" 802.11n.

The "Mid-2010" models all hae one Mini DisplayPort, but the "Mid-2011" models have one or two Thunderbolt ports instead (the 21.5" models have one port and the 27" models have two). All of these connection standards support a maximum of a 30" (2560x1600) display per port (so the "Mid-2011" models with 27" displays can simultaneously support two external displays in addition to the internal one).

Thunderbolt is backwards compatible with Mini DisplayPort-equipped monitors and works with DVI, VGA, dual-link DVI and HDMI adapters as well. As first reported by MacWorld, both the 21.5" and 27" models in the "Mid-2011" line support "Target Display Mode" from external Thunderbolt-equipped sources (so they can be used as an external display from another Thunderbolt-equipped Mac -- like the "Early 2011" MacBook Pro line -- but not with older Mini DisplayPort-equipped Macs). By contrast, the older "Mid-2010" iMac models with 27" displays support Target Display Mode from external DisplayPort sources, but not Thunderbolt ones. "Mid-2010" iMac models with 21.5" displays do not support Target Display Mode at all.

Identification Differences

Externally, the "Mid-2011" and "Mid-2010" iMac line both unfortunately use the A1311 and A1312 model numbers as the previous "Early 2009" iMac models that share the same case, but they can be differentiated by unique EMC numbers (inconveniently located under the "foot" supporting each system). For the 21.5" and 27" model in each line, respectively, the "Mid-2010" models have EMC numbers of 2389 and 2390, whereas the "Mid-2011" models have EMC numbers of 2428 and 2429.

In software, the 21.5" and 27" models in the "Mid-2010" line are assigned model identifiers of iMac11,2 and iMac11,3, whereas the models in the "Mid-2011" line are assigned iMac12,1 and iMac12,2. When either the EMC number or model identifier are combined with processor speed, it is possible to pinpoint the exact model. Alternately, you can type a serial number into EveryMac.com's Ultimate Mac Lookup potentially for an exact match.

Internal Differences

Internally, these lines have significant processor, graphics processor, and architecture differences, although they share the same type of RAM. Officially, all support up to 16 GB of 1333 MHz PC3-10600 DDR3 SDRAM, but third-parties have determined that the 27" models in both lines actually are capable of supporting up to 32 GB.

Perhaps most notably, the "Mid-2011" models have Quad Core "Sandy Bridge" processors across the line with a DMI (Direct Media Interface) that is twice as fast. Each processor in the "Mid-2011" line is mounted on an LGA 1155 (H2) processor socket whereas the "Mid-2010" models have slower processors mounted on an older LGA 1156 (H) socket.

Also notable, the hard drive/SSD in the "Mid-2010" models support 3 Gb/s Serial ATA 2.0. As first discovered by site sponsor OWC, the "Mid-2011" models, by contrast, support the faster 6 Gb/s Serial ATA 3.0 standard for the hard drive/SSD after installing the iMac EFI Update 1.6.

Comparison Charts

The major configuration differences between the stock "Mid-2011" models and "Mid-2010" Aluminum model that each immediately replaced are summarized below for your convenience. Please refer to the specs page for the model of interest for complete details.

The entry-level model gains a faster quad core processor and a faster graphics processor with twice the VRAM along with the faster architecture:

The low-middle range model gains a faster quad core processor and an improved graphics processor along with the faster architecture:

The middle-high end model gains a faster quad core processor and an improved graphics processor along with the faster architecture and dual external display support.

The high-end model gains a modestly faster processor (albeit with a smaller L3 cache) and graphics processor as well as the faster architecture and dual external display support:

Comparison Summary

Ultimately, most users likely would be quite happy with the faster processors, improved graphics processors, and other tweaks provided by the "Mid-2011" iMac models when compared to the models each replaced, but the "Mid-2010" iMac models also remain well worth consideration, particularly given discount prices on the used market.

In the US, site sponsor Adorama sells new iMac models with free shipping. Other World Computing sells used and refurb iMac models at bargain prices with free shipping, as well. Finally, if you need to sell an iMac, A+ BBB-rated Cash for Your Mac will buy your older iMac with an instant quote and prompt payment.

In the UK, site sponsor Hoxton Macs sells used iMac models with a one-year warranty and free next day delivery throughout the UK. Delivery across Europe also is available starting at just £9.99 for two-day delivery to France and Germany.

Please refer to the Ultimate Mac Comparison feature to dynamically compare any iMac model to any other G3 or later Mac.