What are all the differences between the iMac Pro and the 27-Inch "2020" iMac models?

This Q&A compares the iMac Pro with the 27-Inch "2020" iMac models available when the iMac Pro was discontinued. This Q&A has been updated subsequently and can be quite useful for anyone buying or selling one of these models on the used market.

The iMac Pro models -- formally referred to as the "Late 2017" line -- are the iMac Pro "8-Core" 3.2 27" (5K), "10-Core" 3.0 27" (5K), "14-Core" 2.5 27" (5K), and "18-Core" 2.3 27" (5K). The entry-level iMac Pro "8-Core" 3.2 27" (5K) was discontinued on August 4, 2020 and the remaining three configurations received price cuts at the same time. The iMac Pro was discontinued entirely on March 19, 2021.

The 27-Inch "2020" iMac models are the stock iMac "Core i5" 3.1 27" (5K), "Core i5" 3.3 27" (5K), and "Core i7" 3.8 27" (5K) and the configure-to-order iMac "Core i9" 3.6 27" (5K), "Core i7" 3.8 27" (5K; 5700/XT), and "Core i9" 3.6 27" (5K; 5700/XT).

Photo Credit: Apple, Inc. (27" iMac 5K - Left, iMac Pro - Right)

External Differences

The 27-Inch "2020" iMac and iMac Pro models use a very similar external case design (they're even the exact same dimensions), and have sharply tapering sides at the edge of the display, but the iMac Pro is a dark "Space Gray" color.

Both models have highly similar 27" LED-backlit 16:9 widescreen IPS DCI-P3, wide color gamut, "Retina 5K" displays with a gigantic 5120x2880 resolution, as well, but the 27-Inch "2020" iMac models add True Tone technology. True Tone evaluates the color temperature and ambient brightness of your surroundings and dynamically adjusts the display's white balance to match.

For an extra US$500, at the time of system purchase, Apple also offered the 27-Inch "2020" iMac with a "nano-texture glass" display surface to more dramatically reduce glare, which curiously, it did not offer for the otherwise higher-end iMac Pro.

Both models have a 1080p "FaceTime HD" webcam, but the iMac Pro has four integrated microphones rather than just a three-mic array. The iMac Pro also is noticeably quieter which makes it particularly valuable for audio production work.

Connectivity Differences

Both the 27-Inch "2020" iMac and iMac Pro have four USB 3 (USB-A) ports, an awkwardly located SDCX card slot, and an analog 3.5 mm headphone jack. They also both have 802.11ac Wi-Fi and Bluetooth 5.0 capability.

However, the non-Pro iMac only has two Thunderbolt 3 (USB-C) ports and Gigabit Ethernet whereas the iMac Pro has four Thunderbolt 3 (USB-C) ports and faster Nbase-T (10-gigabit) Ethernet by default. The 27-Inch "2020" iMac could be equipped with 10-Gigabit Ethernet at the time of purchase as a US$100 upgrade.

Identification Differences

Just compared to one another, the 27-Inch "2020" iMac and "Late 2017" iMac Pro models can be identified by color, or more precisely, by Model Number, A2115 for the "2020" iMac and A1862 for the iMac Pro. However, the identifiers for the non-pro iMac models are shared by other systems and are not as useful for specific identification.

Accordingly, these systems can be more uniquely differentiated by Model Identifier in software and EMC Number externally. Just as the site has for other Macs for more than two decades, EveryMac.com has carefully hand documented these details for your convenience:

iMac Model	Model ID	EMC No.
iMac (2020, 5K)	iMac20,1/iMac20,2	3442
iMac Pro (Late 2017)	iMacPro1,1	3144

Additionally, EveryMac.com's Ultimate Mac Lookup feature also can uniquely identify each of these models by their serial numbers.

Internal Differences

Internally, the 27-Inch "2020" iMac and "Late 2017" iMac Pro have some common aspects, but some important differences, as well. Both have onboard SSD storage and are essentially dependent on Thunderbolt 3 ports for connectivity to fast external storage.

The 27-Inch "2020" iMac models have "Comet Lake" (10th Gen) processors and Radeon Pro graphics. The RAM is beautifully easy to upgrade via a simple access door. As first determined by site sponsor OWC, the SSD in these models, by default, is soldered onboard and cannot be upgraded, although it might be possible to upgrade some configurations if they also are equipped with 4 TB or 8 TB SSDs at the time of purchase.

The "Late 2017" iMac Pro models, by contrast, use more advanced -- but older -- Xeon W processors and Radeon Pro Vega graphics. It is possible to upgrade the RAM (just needlessly difficult) and although it is removable, it may or may not be possible to upgrade the SSD. The iMac Pro models are quieter with a more advanced cooling system, as well.

Comparison Chart

The major differences between the current 27-Inch "2020" iMac and the current iMac Pro options are summarized below. Please refer to the specs page for the model of interest for complete details:

	27" 5K 2020	Pro Late 2017
Case Color:	Silver	Dark Gray
Processor Speed:	3.1, 3.3, 3.8 GHz*	3.0, 2.5, 2.3 GHz†
Processor Type:	6 Core i5/ 8 Core i7*	10, 14, 18 Cores†
Processor Family:	Comet Lake	Xeon W
Processor Mounting:	LGA 1151	LGA 2066
DDR4 RAM:	2666 MHz	2666 MHz (ECC)
Standard RAM:	8 GB	32 GB
Maximum RAM:	128 GB	512 GB
RAM Slots:	4	4
RAM Upgrade:	Easy (Door)	Difficult
Standard Storage:	SSD	SSD
Standard Graphics:	Radeon Pro 5300 Radeon Pro 5500 XT	Radeon Pro Vega 56
Dedicated VRAM:	4, 8 GB	8 GB
Display Size:	27-Inch	27-Inch
Display Resolution:	5120x2880	5120x2880
True Tone:	Yes	No
Thunderbolt 3:	Two	Four
Ethernet:	Gigabit	10-Gigabit
Microphones:	Three	Four
Order Number (US):	MXWT2LL/A MXWU2LL/A MXWV2LL/A	MHLV3LL/A
EMC Number:	3442	3144
Model Identifier:	iMac20,1/iMac20,2	iMacPro1,1
2020 Price (US):	US$1799 US$1999 US$2299	US$4999 US$5799 US$6599
2020 Price (UK):	£1799 £1999 £2299	£4999 £5799 £6599
2020 Price (CA):	C$2399 C$2649 C$3079	C$6299 C$7259 C$8219
2020 Price (AU):	A$2799 A$3099 A$3549	A$7299 A$8499 A$9699

* By custom configuration, the iMac "Core i5" 3.3 27" (5K), and "Core i7" 3.8 27" (5K) could be configured with a 3.6 GHz 10-Core "Core i9" processor (I9-10910) for an extra US$500 or US$400, respectively. This processor has a 20 MB level 3 cache and Turbo Boost up to 5.0 GHz. EveryMac.com also has documented these custom configurations as its own model.

† An earlier iMac Pro model with a 3.2 GHz 8-Core Xeon W-2140B processor was discontinued August 4, 2020. EveryMac.com documents this model as the iMac Pro "8-Core" 3.2 27-Inch (5K, Late 2017). Apple discontinued the iMac Pro entirely on March 19, 2021.

Comparison Summary

Ultimately, compared to the newer 27-Inch "2020" iMac, the older iMac Pro -- first introduced in 2017 -- definitely was showing its age despite its August 2020 price cut.

Compared to its non-Pro contemporary, the iMac Pro retains a 30% or so edge in multicore performance, but it actually is slower in single core performance, despite its significantly higher pricetag (when both systems were new). The iMac Pro has better connectivity, better mics, and is quieter and cooler, but only those with high-end audio, video, and scientific software that can take full advantage of multicore processors really still might be able to justify the much higher price. Time is money, after all, but most users would be better served with the significantly cheaper 27-Inch "2020" iMac when both models were new. On the used market, the iMac Pro value proposition may have changed somewhat, though.

In the US, site sponsor Adorama sells new iMac models with free shipping. Other World Computing sells used and refurb iMac Pro models at bargain prices with free shipping, as well. Finally, if you need to sell an iMac, A+ BBB-rated Cash for Your Mac will buy your older iMac with an instant quote and prompt payment.

In the UK, site sponsor Hoxton Macs has a good selection of used and refurbished iMac Pro models with a one-year warranty and free next day delivery throughout the UK. Delivery across Europe also is available starting at just £9.99 for two-day delivery to France and Germany.

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