Apple iMac “Core 2 Duo” 3.33 GHz 21.5″ 2009 Specs

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iMac – BTO/CTO – iMac10,1 – A1311

About this iMac

This device is a BTO/CTO device that is nearly identical to MB950LL/A. We have listed this device separately as it has been configured with an upgraded processor when compared to the base model. This has been done to make it easier to catalog as well as easier to read.

The Apple iMac released in Late 2009 was a 21.5-inch version powered by a 3.33 GHz Intel Core 2 Duo processor. It had a built-in iSight video camera and a vertically-mounted slot-loading DL Super Drive. The FireWire ports were reduced from two to one single slot and there was an additional USB port. The design of the body was made to ensure there was seamless glass to aluminum enclosure. This machine was a statement both on the exterior and interior.

3.33 GHz Core 2 Duo

4 GB

500 GB or 1 TB Hard Drive

Plugged-in

Storage

The a1311 device was built with 500 GB or 1 TB Serial ATA (3Gb/s) hard drive storage with a disk speed of 7200 RPM.

Screen Size and Resolution

The iMac featured a 21.5 inch screen with “glossy” TFT active matrix LCD display and a native resolution of 1920×1080.

Processor& Graphics Processing Unit (GPU)

The iMac had the Mac OS X 10.6.1 (10A2155) operating system pre-installed on it. It was powered by a 3.33 GHz Intel Core 2 Duo (E8600) processor. Its graphics processor was the NVIDIA GeForce 9400M graphics with 256 MB of memory shared with the system.

Memory & Architecture

The device was built with a 6 MB on-chip level 2 cache with a frontside bus of1333 MHz and with 4 GB of 1066 MHz PC3-8500 DDR3 its RAM. It’s designed was centered on a 64-Bit architecture.

Upgradability

Although the iMac came with 4 GB of RAM it could be upgraded to up to 16 GB of RAM.
The Operating System of the iMac can also be upgraded from its pre-installed Mac OS X 10.6.1 (10A2155) to up to current MacOS. This iMac was also able to run Windows XP SP2 (32-Bit) and more recently Windows 7 (64-Bit).
This iMac had the following dimensions of 45.1 cm, 52.8 cm, 18.85 cm and a weight of 20.5 lbs. (9.3 kg).

Inclusive Features

The iMac includes the following features and ports:

A Power Adapter (100V-240V, 241W maximum)
Standard AirPort Extreme (802.11a/b/g/n).
Gigabit Ethernet
One FireWire 800 port
8X DL “Super Drive”
A Mini DisplayPort allowing dual and mirroring operations with resolutions of up to 2560×1600.
Built-in Stereo Speakers

Introduced:October 20, 2009		Discontinued: July 27, 2010
Screen Size and Resolution		Memory
Screen Size	21.5 inches TFT	Level 1 Cache	32k/32k
Resolution	1920×1080	Level 2/Level 3 Cache	6 MB (on-chip)
Processor		RAM Type	PC3-8500 DDR3
Processors	1 (2 Cores)	Min. RAM Speed	1066 MHz
Architecture	64-Bit	Standard RAM	4 GB
Speed	3.33 GHz	Maximum RAM	16 GB
Type	Core 2 Duo (E8600)	RAM Slots	4
Processor Upgrade	LGA 775 (Socket T)	Motherboard RAM	None
FPU	Integrated	Graphics
System Bus Speed	1333MHz	Video Card	GeForce 9400M
Cache Bus Speed	3.33 GHz (Built-in)	VRAM Type	Integrated
ROM/Firmware	EFI	Standard VRAM	256 MB
EFI Architecture	64-Bit	Maximum VRAM	256 MB
Storage		Inclusive Features and Ports
Standard Storage	500 GB, 1 TB HDD	Standard Optical Drive	8X DL “Super Drive”
Storage Speed	7200 RPM	Standard Ethernet	10/100/1000Base-T
Storage Dimensions	3.5” (26.10 mm)	Standard Modem	None
Storage Interface	Serial ATA (3 Gb/s)	Standard Air Port	802.11a/b/g/n
Battery		Standard Bluetooth	2.1+EDR
Type	N/A	USB Port 2.0	4
Battery Life	N/A	FireWire Ports	1 (800)
Description		Keyboard	Apple Wireless Keyboard
Case Type	All-in-One	Inclusive Input	Mighty Mouse
Form Factor	iMac (Late 2009)	S-Video Output	None
Apple Order No	BTO/CTO	Microphone	1 (Built-in)
Apple Subfamily	Late 2009	Headphone	1
Apple Model Number	A1311 (EMC 2308)	Sound Out	1
Model ID	iMac 10.1	Power Adapter	1

Identifier reference: CTOMB950LL/A, A1311, EMC 2308, iMac10,1. Use these together because one Apple identifier can sometimes cover multiple configurations.

Last reviewed by Techable: August 19, 2025Identifiers checked: order number, A-number, EMC, and model identifier when available.

Model summary

This iMac at a glance

Family: iMac
Order Number: CTOMB950LL/A
Model Number: A1311
EMC: 2308
Model ID: iMac10,1
Year: 2022

Use the order number, A-number, EMC, and model identifier together when comparing, buying, or selling this device.

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Search by A-number, EMC, order number, or model identifier.

Next steps

Use the spec table to confirm the exact device, then choose the right lookup, buy, or sell path.

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Common questions

Is CTOMB950LL/A the same as A1311?

Not exactly. CTOMB950LL/A usually points to a specific retail configuration, while A1311 identifies the broader Apple hardware family. Always check the EMC and model identifier too.

What iMac is model A1311?

A1311 is the Apple A-number shown for this iMac family. Use the order number, EMC, and model identifier on this page to narrow the exact configuration.

What does EMC 2308 mean?

The EMC number is another Apple hardware identifier. It helps separate closely related models that may share a similar name, year, or A-number.

Can the RAM or SSD be upgraded?

Check the spec table for the exact configuration. Many newer Apple Silicon Macs have memory and storage integrated into the board, so RAM and SSD upgrades are often not practical after purchase.

What macOS versions work with this model?

Use the model identifier, release year, and processor family from the spec table when checking macOS compatibility. Compatibility can change as Apple releases new macOS versions.

Is this iMac still worth buying used?

It can be, depending on price, battery health, memory, storage, and condition. Compare this exact order number and model identifier against similar Techable listings before buying.

How much is this iMac worth?

Value depends on RAM, storage, battery health, cosmetic condition, accessories, and market demand. Use the SellMac path on this page for a quote or use the identifiers here when comparing resale prices.

What should I search if this page is not the exact configuration?

Search the order number first when available, then compare the A-number, EMC, model identifier, year, chip, RAM, and storage. The same A-number can cover more than one configuration.

Handling multiple devices?

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