Apple iMac (20-inch, Mid 2009) vs Apple iMac (21.5-inch, Late 2011)

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iMac (20-inch, Mid 2009) compared with iMac (21.5-inch, Late 2011)

	AppleiMac (20-inch, Mid 2009)	AppleiMac (21.5-inch, Late 2011)
Overview
Released
Released	April 2009	August 2011
Performance
Processor
Processor	Intel Core 2 Duo 2 GHz (iMac Mid 2009) or Intel Core 2 Duo 2.26 GHz (iMac Mid 2009)	Intel Core i3 3.1 GHz (iMac Late 2011)
CPU cores
CPU cores	2	2
Graphics
Graphics	NVIDIA GeForce 9400M (256 MB shared DDR3)	AMD Radeon HD 6750M (256 MB GDDR5)
Memory
Memory	1 GB, 2 GB or 4 GB	2 GB, 4 GB or 8 GB (better)
Storage
Storage	160 GB to 320 GB (better)	250 GB
CPU
CPU	2.0 or 2.26 GHz Core 2 Duo with 3 MB shared L2 cache and 1066 MHz frontside bus. The retained configuration table says 2.6 GHz, but its processor description and Apple's July 2011 education price list confirm 2.26 GHz; exact Intel SKU not established.	3.1 GHz dual-core Intel Core i3 with 3 MB shared L3 cache. The English specification and maker education price list confirm dual-core i3; conflicting translated regional processor descriptions are not used. Exact Intel SKU unestablished.
GPU
GPU	NVIDIA GeForce 9400M with 256 MB shared DDR3 according to the retained maker specification; contemporary EveryMac coverage describes 128 MB at launch, so the retained maker value is used.	AMD Radeon HD 6750M with 256 MB GDDR5.
Memory type
Memory type	Two SO-DIMM slots for 1066 MHz DDR3; configurations A/B have 1 GB standard and C has 2 GB. Factory options are 2 or 4 GB; the retained specification supports up to 8 GB, which is not listed as a factory configuration.	1333 MHz DDR3; 2 GB standard in one module, configurable to 4 GB (two 2 GB) or 8 GB (two 4 GB).
Storage type
Storage type	160 or 320 GB 7200 rpm Serial ATA hard drive; slot-loading 8x SuperDrive with 4x double-layer DVD burning.	250 GB 7200 rpm Serial ATA hard drive; slot-loading 8x SuperDrive with 4x double-layer burning.
Display
Screen size
Screen size	20″	21.5″
Resolution
Resolution	1680 × 1050	1920 × 1080 (better)
Brightness
Brightness	290 nits	–
Display type
Display type	Glossy TFT active-matrix LCD with millions of colours; typical contrast 800:1 and 160-degree horizontal and vertical viewing angles. Panel technology and refresh rate unpublished.	LED-backlit glossy TFT active-matrix LCD with millions of colours. Panel technology, brightness and refresh rate are not published.
Connections
Ports
Ports	4 × USB-A, Ethernet, headphone jack	4 × USB-A, SD card slot, Ethernet, headphone jack
Ethernet
Ethernet	1 Gb/s	1 Gb/s
External displays
External displays	Up to 1	Up to 1
Wi-Fi
Wi-Fi	802.11n draft	802.11n
Camera
Camera	iSight camera	FaceTime HD camera
Back ports
Back ports	Four USB 2.0 ports on the computer, plus two on the keyboard; FireWire 800 at 7 W, Mini DisplayPort, Gigabit Ethernet, headphone/optical digital output and line-in/optical digital input. Bluetooth is not published in this exact model specification.	Four USB 2.0 ports on the computer, plus two on the wired keyboard; Mini DisplayPort, FireWire 800 at 7 W, SDXC card slot, Gigabit Ethernet, headphone/optical output and audio line-in/optical input. This education model has no published Thunderbolt or Bluetooth specification.
External displays
External displays	Built-in display and one external display up to 2560 × 1600 simultaneously; extended desktop or mirroring, with optional DVI, VGA or dual-link DVI adapters.	Built-in display and one external display up to 2560 × 1600 simultaneously; extended desktop or mirroring.
Speakers
Speakers	Built-in stereo speakers and microphone; internal 24 W digital amplifier and support for Apple Stereo Headset microphones.	Stereo speakers with two internal 20 W amplifiers; microphone and support for Apple iPhone headset microphone.
Keyboard and mouse
Keyboard and mouse	Apple Keyboard and Mighty Mouse.	Wired Apple Keyboard with Numeric Keypad and Apple Mouse with scroll ball.
Design and power
Type
Type	All-in-one	All-in-one
Weight
Weight	9.1 kg	8.8 kg (better)
Width × depth × height
Width × depth × height	485 × 189 × 469 mm	528 × 188.5 × 451 mm
Operating system
Operating system	macOS	macOS
Size and weight detail
Size and weight detail	Maker reference weight; actual weight varies with configuration and manufacturing process.	Maker reference weight; actual weight varies with configuration and manufacturing process.
Power supply
Power supply	Maximum continuous power 200 W; 100–240 V AC, 50–60 Hz.	Maximum continuous power 205 W; 100–240 V AC, 50–60 Hz.
In the box
In the box	Education institution model. Contemporary EveryMac coverage records April 2009 release; a maker-confirmed first delivery day is unavailable. Launch configuration A includes Leopard and iLife ’09; later B/C specifications list Snow Leopard and iLife ’11, with their introduction dates unestablished.	Education institution model with Mac OS X Lion and iLife. August 2011 month precision follows contemporary MacRumors ordering coverage and 9to5Mac shipment scheduling, corroborated by the maker price list dated 8 August; that price date is not treated as a first delivery day.