24-inch M1 iMac vs 21.5-inch iMac: What’s the Difference

BY Parth Shah

Published 21 Apr 2021

24-inch iMac

After months of leaks and speculations, Apple finally unveiled the redesigned 24-inch iMac at its ‘Spring Loaded‘ event. The 24-inch iMac brings a bigger display, brighter colors, a thinner profile, and a change of heart, swapping the Intel CPUs with the company’s in-house M1 chip. On top of that, you also get upgrades in mics, speakers, and a web camera, something that’s essential these days. Read along to find all the differences between the old 21.5-inch iMac and the new 24-inch iMac.

21.5-inch Intel iMac vs 24-inch M1 iMac: What’s the Difference

Design and Display

  • 21.5-inch iMac – 52.8 x 37.8 x 17.5 cm, 5.67 kg
  • 24-inch iMac – 54.7 x 46.1 x 13 cm, 4.46 kg

As you can see from the dimensions above, nothing much has changed in terms of overall size. However, Apple has smartly shrunk down the bezels while increasing the display size. The overall weight is also down by more than 1 kg, which is commendable.

iMac design

  • 21.5-inch iMac – Full-HD sRGB display with 1920×1080 resolution
  • 24-inch iMac – 4.5K Retina display with 4480×2520 resolution

The display is one area where you will find an immediate upgrade over the outgoing 21.5-inch iMac. The 4.5K  Retina Display is sharp, and it comes with all the goodies such as 500 nits of brightness, ProMotion, True Tone, and P3 wide color support.


  • 21.5-inch iMac – 2.3GHz dual-core 7th-generation Intel Core i5 processor, Turbo Boost up to 3.6GHz
  • 24-inch iMac – Apple M1 Chip

The 2021 iMac has received the biggest performance gains in years. Unsurprisingly, Apple has switched the Intel chips with the in-house M1 architecture. The swap has enabled the company to deliver an all-in-one machine in a striking thinner profile.

Thanks to the power-efficient nature of the new M1 chip, Apple was able to dramatically reduce the logic board and internal components of the new iMac. The entire cooling system has been replaced with two small fans, which are more than enough to cool the new iMac without making any noise.

iMac processor

The 21.5-inch started with a 3.6GHz quad-core Core i3 with a maximum clock speed under Turbo Boost of 3.6GHz. Two optional upgrades were available, with the highest being a 6-core Core i7 clocked at 3.2GHz, 4.6GHz under Turbo Boost.

Apple claims the new M1 chip brings 85% faster CPU performance and 2x faster GPU performance than the 21.5-inch iMac. You will be able to edit up to five 4K streams simultaneously, or one 8K stream in Final Cut Pro. Machine Learning apps will also be up to 3x faster thanks to the 16-core Neural Engine in the M1 chip.

Do note that the base iMac features a 7-core GPU, while the mid-range variant features an 8-core GPU.

Storage and RAM

  • 21.5-inch iMac – Up to 256GB SSD, and 8GB 2133MHz memory, configurable to 16GB
  • 24-inch iMac – 256GB SSD or 512GB SSD, configurable to 1TB or 2TB for 4-port model. 8GB unified memory, configurable to 16GB

Apple has left no stone unturned when it comes to storage options on the new 24-inch iMac. While most users opt for an external SSD to expand the storage, it’s good to see more options out of the box. I strongly feel that Apple has missed the mark with RAM options. It tops out at 16GB. It should be more than enough for the majority, but power users may find it limiting in certain situations.


  • 21.5-inch iMac – 1080p FaceTime HD camera
  • 24-inch iMac – 1080p FaceTime HD camera with M1 image signal processor

iMac camera

The 24-inch sticks to a 1080p FaceTime camera but takes advantage of the M1’s Image Signal Processor and the Neural Engine to improve the picture with higher dynamic range, better noise reduction, and improved auto exposure.

Audio Recording

  • 21.5-inch iMac – Standard microphone
  • 24-inch iMac – Three-mic array setup

This was long overdue, and it’s a welcome change in today’s work from home environment where everything is relying on Microphone, Camera, and Speakers to handle meetings and online conferences.

The 24-inch iMac improves over the standard 21.5-inch iMac by using the three-mic array, a high signal-to-noise ratio and directional beamforming.


  • 21.5-inch iMac – Stereo speakers
  • 24-inch iMac – High-fidelity six-speaker system

Be it iPhone, iPad, or MacBook, Apple products always have a capable sound system. The 2021 iMac takes the whole experience to the next level with a high-fidelity six-speaker system with force-canceling woofers, wide stereo support, and support for spatial audio when playing video with Dolby Atmos.

iMac as entertainment

Apple claims that you won’t need external speakers as the built-in sound system is powerful enough to meet your entertainment needs.

Keyboard and Mouse

  • 21.5-inch iMac – Magic keyboard and wireless mouse
  • 24-inch iMac – Magic keyboard with Touch ID and wireless mouse

The new iMac also benefits from a refined Magic Keyboard, which includes a few extra additions, but importantly has Touch ID for one-touch security. The four-port version ships with the Magic Keyboard with Touch ID, but while the two-port gets the updated Magic Keyboard without Touch ID by default, it can be upgraded to use the Touch ID version. Speaking of ports, let’s talk about the port selection. Shall we?

New Apple Keyboard with Touch ID

Port Selection

  • 21.5-inch iMac – Range of port selection
  • 24-inch iMac – Thunderbolt USB C port

The dongle life is impossible to ignore. We are not surprised to see the change though. The old 21.5-inch iMac used to come with a variety of ports such as USB A, headphone jack, microSD, two Thunderbolt 3 (USB-C) ports, and Gigabit Ethernet. The 24-inch removes all the crowd and comes with two Thunderbolt 4 (USB-C) on the base model and four Thunderbolt 4 (USB-C) on the mid to higher variants.

iMac ports

The new 24-iMac is so thin that Apple had to remove the headphone jack from the back and reposition it to the side profile of the device.

Color Choices

  • 21.5-inch iMac – Silver
  • 24-inch iMac – Up to seven colors

The 21.5-inch iMac used to come in only one color option – Silver. The 24-inch iMac comes with a rainbow of color options to choose from. Apple is bringing out the two-port 24-inch iMac in four colors, rising to seven colors for the four-port version. The available color options are Orange, Red, Silver, Green, Violet, Blue, and Yellow. A darker shade at the back of the iMac and a lighter shade at the front chin.

24-inch M1 iMac


  • 21.5-inch iMac – Starts at $1099
  • 24-inch iMac – Starts at $1299

Even though the 24-inch iMac starts at a higher price tag, we feel that it’s justifiable considering the number of upgrades you are getting this time around.

Should You Make a Switch?

In one word – Absolutely. The new 2021 24-inch iMac is a step in the right direction with the ground-breaking Apple M1 chip, striking thinner design, better camera, mic, speakers, reduced bezels, and exciting new color. It’s the perfect replacement for the outgoing 21.5-inch iMac. Those using 27-inch iMac should wait for few months as we expect Apple to give this one a size bump with a newer M-series of processor down the road.

Are you interested to learn more about the 24-inch iMac? Read our dedicated post to find the top features of the M1 iMac.