IMac (Intel-based)


The iMac is a series of all-in-one desktop computers designed, manufactured, and sold by Apple Inc. Between 2006 and 2022, the iMac series used chipsets based on Intel architecture. While sold, it was one of three desktop computers in the Mac lineup, serving as an all-in-one alternative to the Mac Mini, and sat below the performance range Mac Pro. It was sold alongside a higher-end, Xeon-based iMac Pro from 2017 to 2021.
The earliest Intel iMacs reused the same white polycarbonate enclosure as the iMac G5. Later models shifted to aluminum and plastic, and then a unibody aluminum case. The iMacs released after October 2012 also featured a much thinner display, with the edge measuring just 5 mm. This design would persist until the line was discontinued.
As part of the Mac transition to Apple's own processors, the Intel-based iMac was succeeded by the Apple silicon iMac beginning in 2021. Apple discontinued the 21.5-inch Intel iMac the same year, with the 27-inch model discontinued in March 2022, following the announcement of the Mac Studio and 27-inch Apple Studio Display.

Overview

The iMac is an all-in-one personal computer. The machine has an integrated Liquid-crystal display, with the computer components integrated either behind the screen or below it in a "chin". An L-shaped aluminum foot allows the screen to be tilted but does not offer height adjustment. Ports for connecting peripherals are located on the bottom edge of the computer; an optical drive is located along the right edge of certain models. If wireless peripherals are used, the iMac's only cable is the power cord routed through the back.
On June 22, 2020, Apple's Worldwide Developer Conference keynote included the announcement that future Macintosh computers would transition yet again to Apple's own ARM-based system-on-chips; in April 2021, Apple unveiled a redesigned iMac based on its M1 system-on-chip.

Models

White (2006)

At the Macworld Conference and Expo on January 10, 2006, Steve Jobs announced that the new iMac would be the first Macintosh to use Intel processors. The introduction of the new iMac alongside the MacBook Pro was the start of the Mac transition to Intel processors, six months earlier than the timetable Apple established. It retained the look and features of the preceding iMac G5, with a white plastic enclosure less than at its thinnest edge. It also shipped at the same price points. The first Intel iMac featured an Intel Core Duo processor and PCI Express graphics processing units. Like the iSight revision of the iMac G5, the machine was not designed to be user-serviced, and almost all components are difficult to access; the exception are the random-access memory slots, which are found on the bottom of the machine. One update from the iMac G5 was the addition of a Mini-DVI port that allowed for extending the computer contents to a second monitor versus mirroring the image.
In early February 2006, Apple confirmed reports of video display problems on the new Intel-based iMacs. When playing video on Apple's Front Row media browser, some 20-inch iMacs showed random horizontal lines, ghosting, video tearing and other problems. The problem was fixed with a software update.
An education-only model of the iMac shipped in July 2006 that replaced the eMac in Apple's lineup. This model came with a lower starting price, but had a smaller hard drive, integrated graphics processor, and a combo optical drive rather than the SuperDrives on other iMacs. The entire iMac lineup was refreshed with a Core 2 Duo chip and a lower price in September 2006. Apple added a new 24-inch model with an IPS panel display and a resolution of 1920 × 1200, making it the first iMac to be able to display 1080p content in its full resolution, and a VESA Flat Display Mounting Interface.
These early iMacs were generally praised, with Walt Mossberg writing that the Intel-based iMac remained the best desktop personal computer available. Performance depended on the software; PCMag and others found that software unoptimized for Intel processors ran slowly, especially games that were already poorly optimized for the Mac. Macworld recommended potential buyers hold off until there was more software for Intel machines. Other criticisms included the low amount of starting memory, lack of user-serviceability, and the chin, which Anand Lal Shimpi called "bottom-heavy".

Specifications of White iMacs

Aluminum (2007–2009)

In August 2007, Apple introduced a complete redesign of the iMac, featuring an aluminum, glass and plastic enclosure. It has a black, plastic backplate that is not user-removable. The 17-inch model was completely removed from the lineup, and it was available only in 20-inch and 24-inch models. The 24-inch model's display has better contrast and color conformity over a wide range of viewing angles. There is only one visible screw on the entire computer, located at the base of the iMac for accessing the memory slots. A plastic model from the previous generation remained as an option for education buyers.
In March 2009, Apple released a minor refresh of the iMac line. Changes included a fourth USB port, replacement of two FireWire 400 ports with one FireWire 800 port, replacement of mini-DVI with Mini DisplayPort, and a slightly redesigned base which is vertically thinner. Otherwise, the exterior design is almost identical to the 2007 and 2008 models. The models were one 20-inch configuration and three 24-inch configurations.
Apple doubled the default RAM and hard-disk size on all models, moving the RAM to the DDR3 specification. This revision also introduced a new, smaller, and more compact Apple Keyboard that excluded the numeric keypad and forward delete key in favor of the fn + Delete keyboard shortcut by default. Users could, however, replace this version with a more traditional, full-size model with a numeric keypad by requesting Apple to build their machine to order through its online store.

Specifications of Aluminum iMacs

Unibody (2009–2011)

In October 2009, a 16:9 aspect ratio screen was introduced in 21.5" and 27" models, replacing the 20" and 24" 16:10 aspect ratio screens of the previous aluminum models. The back is made of aluminum instead of plastic, and is a continuation of the aluminum body from the front and sides. Video card options entirely switched to AMD, except for the standard onboard Nvidia card in the base smaller model. The iMac's processor selection saw a significant increase.
The Intel i-series chips are introduced to Mac for the first time on the higher-spec 27-inch models.
Default RAM has also been increased across the iMac range. With the advent of the larger screens, Apple doubled the number of memory slots from two to four. Consequently, the maximum memory capacity was also doubled, and for Intel Core i-series, quadrupled, to 32 GB.
The 27-inch models of the line became the first to offer Target Display Mode, allowing the iMac to be used as an external display for another Mac computer when connected via Mini DisplayPort, a feature that was extended to the 21.5-inch models onwards with the introduction of Thunderbolt.
The Mid 2010 iMac 27" has AMD Radeon HD5650 and HD5750 graphic cards. Both cards cannot support the low-level Metal API, preventing this model from upgrading to Mojave and Catalina. AMD had developed a firmware upgrade that would allow both graphic cards to support Metal and Mid 2010 iMac to be upgraded to latest macOS, but Apple had refused to certify them.
The Late 2011 Unibody iMac is also the last model to include an internal SuperDrive.

Specifications of Unibody iMacs

Slim Unibody (2012–2017)

In October 2012, a new iMac model was introduced that featured a smaller body depth than the previous models, measuring 5 mm at its thinnest point, and without an internal SuperDrive. This was partly achieved by using a process called Full Lamination. The display and glass are laminated together, eliminating a 2 mm gap between them. The 21.5-in and 27-inch screens remained at their previous resolutions, 1920 × 1080 and 2560 × 1440 respectively.
As with the 2009 model, memory has been upgraded; the standard specification is now 8 GB, with the 21.5-in model supporting up to 16 GB and the 27-inch model supporting up to 32 GB. It was reported that the 21.5 in iMac would have non-replaceable soldered memory similar to the MacBook Air and Retina display MacBook Pro though tear-downs show that it uses removable memory but accessing the modules requires ungluing the screen and removing the motherboard. The 27-inch version features an access port to upgrade memory without disassembling the display. Apple also upgraded the computers' processors, using Intel's Ivy Bridge microarchitecture-based Core i5 and Core i7 microprocessors.
Video cards are now Nvidia as standard. USB 3.0 ports were included for the first time. The 2012 iMac also features the option of a Fusion Drive which combines an SSD and a conventional HDD to create more efficient and faster storage. Apple also removed the built-in optical drive starting with the 2012 model.
On March 5, 2013, Apple quietly announced an education-only version of the iMac, with less powerful specs for a cheaper price. It included a 3.3 GHz dual-core Intel Core i3 processor, 4 GB memory, a 500 GB hard drive and Intel HD Graphics 4000, retailing for US$1,099, $200 cheaper than the base-level consumer iMac.
On September 24, 2013, the 2012 iMac model was updated with 4th-generation Intel Haswell processors and Nvidia 7xx series GPU, promising up to 1.4× improvements in performance. It also has 802.11ac Wi-Fi, which is capable of reaching speeds up to 1300 Mbit/s and PCIe-based flash storage, offering up to 1.5× the performance of previous Ivy Bridge unibody iMacs. This applies to both the Fusion Drive and pure-SSD options. These became the last iMacs to offer Target Display Mode, as the Retina line introduced the following year are incompatible with the feature due to resolution differences.
At WWDC on June 5, 2017, a refreshed model was added with Kaby Lake processors and Bluetooth 4.2 support. Apple retailed the 21.5-inch model until October 29, 2021. It was sold in a single stock configuration priced at $1,099 with a 2.3 GHz dual-core 7th-generation Intel Core i5 processor. The machine was heavily criticized for its lagging specifications, outdated design, and comparatively high price. The machine, however, was said to be popular among education shoppers. It was the last Mac to have a Fusion Drive, and after having them for 36 years, the last Mac to have a traditional hard drive. It was also the last Apple product not to have a Retina display.