24-inch M1 iMac vs 21.5-inch Intel iMac: Should I Upgrade?

After months of speculation, Apple finally unveiled the new 24-inch iMac at its Spring Loaded event. But, the question is how good it is when compared to the 2015 model. From a super-thin design to the famous M1 chipset, let’s look at the differences between the 24-inch M1 iMac vs 21.5-inch Intel iMac in our comparison.


24-inch M1 iMac21.5-inch Intel iMac
CPUM1 – 8-coreUp to 3.2GHz 6-core Intel i7
GPUM1 – 8-core (7-core for base model)Up to AMD Radeon Vega 20
StorageUp to 2TB SSDUp to 1TB Fusion Drive
RAM8 or 16GB8, 16, or 32GB
Neural engine16-core
Resolution4480 x 2520 (4.5K)4096 x 2304 (4K)
WebcamFaceTime 1080p HD + M1 ISPFaceTime 720p HD
Brightness500 nits500 nits
WiFiWiFi 6 (802.11 ax)Wi-Fi 5 (802.11ac)

Design and Display

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

Well, technically nothing much has changed in terms of overall design between these machines. However, Apple has shrunk down the bezels of its new iMac. This not only helps to decrease the M1 iMac weight down by more than 1 kg but also leaves an opportunity to increase the display size.

Besides that, the new iMac also has a significant advantage when compared to the 21.5-inch iMac. Its 4.5K Retina Display is sharp and comes with all the goodies such as ProMotion, True Tone, and P3 wide color support. Meanwhile, the 2015 iMac only features a Full-HD sRGB display with 1920×1080 resolution.

Additionally, while the 21.5-inch iMac only comes in one color option (Silver), this year’s 24-inch iMac offers a rainbow of color options for you to choose from. The available color options for the M1 iMac are Orange, Red, Silver, Green, Violet, Blue, and Yellow.

Processor & Performance

Thanks to the swap from Intel chips to the in-house M1 chip, the 2021 iMac has received a huge performance boost. With the new chip’s power efficiency, Apple can dramatically reduce the logic board and internal components of the 24-inch iMac. And, this ends up with a much thinner profile. Plus, the entire cooling system has been replaced with two small fans, keeping the new iMac cool without making any noise.

On top of that, the 2015 iMac is equipped with a 7th-gen Intel Core i5 processor and Turbo Boost up to 3.6GHz. Meanwhile, the 24.-inch iMac has the Apple M1 chip which is claimed to brings 85% faster CPU performance and 2x faster GPU performance when compared to the 21.5-inch iMac

With the new iMac, users will be able to edit up to five 4K streams simultaneously or one 8K stream in Final Cut Pro. Also, the Machine Learning apps are 3x faster thanks to the help of a 16-core Neural Engine in the M1 chip. Note that the base model of the 24-inch iMac only has a 7-core GPU, while its mid-range variants feature an 8-core GPU.

The only drawback of the M1 iMac is its lack of support for multiple displays. But, that is not as much of an issue since the iMac is an all-in-one machine.

 21.5-inch Intel iMac 24-inch M1 iMac
  • CPU Benchmark: 896 single-core & 3182 multi-core score
  • Reach 21000 score in Geekbench 4
  • Cinebench OpenGL test result at 118 frames per second (fps)
  • 85% faster CPU performance
  • 2x faster GPU performance
  • Machine Learning apps are 3x faster

Cameras & Speakers

Even though the new M1 iMac still sticks to the 1080p FaceTime camera, it has the advantages of the M1’s Image Signal Processor and the Neural Engine. This means a higher dynamic range, better noise reduction, and improved auto exposure.

This year’s iMac takes the whole experience to the next level with its brand new six-speaker system. Not to mention the force-canceling woofers, wide stereo support, and spatial audio for Dolby Atmos. Also, Apple claims that users won’t need external speakers as the built-in sound system can meet any entertainment needs.

Audio Recording

The new iMac is improved with a three-mic array over the standard microphone of the 21-5in model. This update offers a high signal-to-noise ratio and directional beamforming. This is such a welcome change in today’s work-from-home environment where everything relies on cameras and audio recording to handle meetings and online conferences due to COVID-19.

Keyboard, Mouse, and Ports

The 2021 iMac benefits from a refined Magic Keyboard, which includes major additions like Touch ID for one-touch security. However, this feature is only available as an option on systems with the 7‑core GPU models. Both machines still feature a wireless mouse.

Whether it is a USB A, microSD, or two Thunderbolt 3 (USB-C), the old 21.5-inch iMac comes with a variety of ports. Unfortunately, the new 24-inch model removes pretty much everything for its super-thin design. Now, the 2021 iMac is only left with two Thunderbolt 4 (USB-C) on the base model and four Thunderbolt 4 (USB-C) for higher variants.

RAM & Storage

Like the first three M1 Macs, the 24-inch iMac is also limited to a maximum of 16GB unified RAM. But, we still love that there are two 512GB storage options available. Although users can opt for an external SSD to expand the storage, it’s still good to have more storage options out of the box. Meanwhile, the 21.5 model only has a 256GB SSD option.


While the 21.5 iMac price started at $1099 back in the day, the new 24-inch iMac only cost you $200 more for the base model. The higher-end M1 iMac model with 8-core CPU starts at $1,499. Even though this is still a higher price tag, we feel that it is worth considering because of the numerous upgrades you can get.

Which iMac Should You Buy?

The new M1 iMac is a big step forward for Apple’s iconic all-in-one desktop. From a better camera to faster performance and many more improvements, it is the perfect replacement for the outgoing 21.5-inch iMac. So, unless you’re waiting for a better iMac to be released or looking for a powerful machine like a Mac Pro, then upgrading to the 24-inch iMac is totally worth the price. Additionally, we only suggest skipping this one if you are using last year’s 27-inch model.

Related article: 24-inch iMac vs 13-inch MacBook Air

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