Which professional Mac desktop: iMac and Mac Pro compared
Updated 6 April 2016 with general pricing and component updates.
With every technology buying decision it's very important that you first establish your requirements and your budget. It's not exactly the best use of funds to buy something that's too expensive and does far more than you need. Conversely you wouldn't want to go through this whole process and end up with a cheaper machine that can't cope with your demands twelve months later.
The golden rule is to take your time, know what you want from the machine, and spend an amount you're comfortable with.
If you need a true powerhouse for running Pro level software such as Final Cut Pro X, Logic Pro X, or any number of other demanding applications, then the higher end models are the obvious place to look.
If you just want a capable desktop that will keep up with general computer duties such as web browsing, home video editing, Photoshop, and some gaming then a general iMac will no doubt fill the need. There's also the ability to upgrade certain machines later on, which is either something that appeals or doesn't, depending on whether you want to get out the screwdriver and delve into your Mac (read about How to get into a Mac with a Screwdriver).
Read our iMac reviews
iMac (21.5-inch, Mid 2014) with Fusion Drive review
iMac 21.5-inch and 27-inch (Late 2013) reviews
Read our Mac Pro reviews
Mac Pro Six-Core/3.5GHz (late 2013) review
Apple Mac Pro Quad-Core/3.7GHz (Late 2013) review
There are in fact three types of desktop in the current Apple catalogue: the iMac, Mac Pro, and Mac mini. While the Mac Mini is a solid choice for general home-use, the current iteration isn't exactly a powerful device when compared to its bigger brothers. If you're already considering a Mac Pro, then the chances are you've already ruled out the mini, and wisely so. Another model to cross off your list is the entry-level iMac, which although attractively priced at £899 is internally actually pretty much the same machine as the Mac mini. The Mac mini used to be more of a contender when it came to the decision of which Mac desktop to buy, but the latest generation is not as good as the previous generation of this Mac, so, at least for now, we are not recommending it in this pro focused article. Read: Mac Mini 2014 v Mac Mini 2012
Read our Mac mini reviews
Apple Mac mini (Late 2014) 2.8GHz review
Mac mini (Late 2014) 1.4 GHz review
Apple Mac mini (Late 2012) review
There are three main categories of iMac at the moment - 21.5-inch (1920x1080), 21.5 with 4K Retina display and a 27-inch with 5K Retina display. Ignoring the entry-level iMac, there are common fittings across the remaining range. The 21-inch and 27-inch models feature quad core, Intel Core i5 CPUs (2.8Ghz or 3.1GHz in the smaller machines, and 3.2GHz or 3.3GHz in the larger ones), 8GB of RAM, and 1TB hard drives - another option exists to get 1 or 2TB Fusion Drives on the 27-inch iMac.
The major differences are that as you move up in price you get more powerful graphical capabilities, with the 21-inch models going from Intel HD Graphics to and Intel Iris Pro 6200, and the 27-inch variants arriving with an AMD Radeon R9 M380, M390 or M395.
Unfortunately, iMacs no longer feature user upgradable RAM, meaning if you want to upgrade the RAM, you'll either need to go into an authorised Apple store, or buy it from purchase. Previously, in older iMac versions you were able to easily access the RAM compartment.
The costs of these machines are £1049 (21-inch, 2.8GHz), £1199 (21-inch, 3.1GHz, 4K Retina Display), £1449 (27-inch 3.2GHz, 5K Retina display), £1599 (27-inch 3.2GHz, 5K Retina display), and £1849 (27-inch 3.3GHz, 5K Retina display),
Alongside the off the shelf models you can also use Apple's build to order feature on the website. This gives you the opportunity to upgrade the 21-inch models to 16GB of RAM (£160) and replace the slower spinning hard drive with either a 1TB Fusion drive for £80 (mixture of flash-storage and normal hard drive), 2TB Fusion Drive for an additional £240 or a 256GB flash-storage for £160 and additionally for the 4K Retina display a 512GB flash-storage for an extra £400. There's also the option to upgrade the CPU in the 3.1GHz i5 4K Retina display version to a 3.3GHz i7 for an additional £160.
These prices hold true for the 27-inch models, with the added choices of a 3TB Fusion drive and 1TB flash-storage - prices vary depending on which 27-inch iMac is selected. The processor on the £1599 and £1849 27-inch iMacs can be upgraded from an i5 to a 4Ghz i7 for an additional £200-240 (depending on which model you're buying).
In our review, we said that '[the] stunning Mac Pro is a true workstation class computer'. Since it was unveiled in 2013 the diminutive, cylindrical Mac has been collecting plaudits for design and capability, and it's no wonder. Apple has managed to fit an incredible amount of power into a unit that is barely taller than an iPad. Now we are all waiting for Apple up update this Mac which is now more than a year old. Read: Mac Pro 2016 launch date and spec rumours
The Mac Pro currently comes in two standard configurations, the cheapest of which features a 3.7GHz quad-core, Intel Xeon E5 CPU, Dual AMD FirePro D300 GPUs, 12GB RAM, and 256GB flash-storage, costing £2,499. For a bit more you can move up to the 3.5GHz 6-core, Intel Xeon E5, with 16GB RAM, Dual AMD FirePro D500 GPUs, and 256GB flash-storage, which will set you back £3,299.
As you'd expect from a pro machine there are plenty of upgrades available on the built to order section of the Apple store. These include the following for the £2499 model:
CPU: 3.5GHz 6-Core at £400 / 3.0Ghz 8-core for £1600 / 2.7Ghz 12-core for £2800 RAM: 16GB for £80 / 32GB for £400 / 64GB for £1040 Storage (flash storage): 512GB for £240 / 1TB for £640 Graphics: AMD FirePro D500 for £320 / AMD FirePro D700 for £800
The £299 model has the following additional options:
CPU: 3.0Ghz 8-core for £1200 / 2.7Ghz 12-core for £2400 RAM: 32GB for £320 / 64GB for £960 Storage (flash storage): 512GB for £240 / 1TB for £640 Graphics: AMD FirePro D700 for £480
Of course this is all without a screen, keyboard, mouse, or speakers, which you'll need to provide yourself.
If you're in the market for a Mac Pro then it stands to reason that you're probably not interested in the lower end iMacs, as while they are excellent machines they can't get near the workstation Pros in terms of power. At the high-end though the iMac with 5K Retina display is a very capable machine and can certainly handle some heavy loads.
Obviously the standout feature on the iMac is that wonderful display, which has a resolution of 5120x2880 and also incorporates various new technologies that keep the colours vibrant, accurate, and consistent even at off-axis viewing angles. This is no mere trifle either, as we've used 5K displays that are more expensive than this iMac, and they don't have a thoroughbred computer inside them. Pushing all those pixels isn't easy, but in our tests the iMac was able to run graphically demanding games at high frame rates without issue, and 4K video had no refresh issues or visible smearing.
One advantage the Mac Pro has in this area though, which might seem odd as the device doesn't even have a monitor included, is that it can run three 4K displays at the same time, while the iMac can run a single, external 4K display alongside its own 5K one.
The Core i5 in the iMac doesn't support Hyper Threading Technology, so it lags behind the Mac Pro in that regard, and this will show up in some applications that require deep computational power. In fact our lab tests actually put the iMac behind the 15-inch Retina MacBook Pro in terms of speed. That doesn't mean it's a slouch in any way though, and cost conscious photographers or videographers can be sure that there is much to love in the iMac with 5K Retina display. Of course there is the option to purchase the Core i7 within an iMac instead, so if you're in the market for a Hyper Threading-enabled iMac, you might want to invest a little more in a Core i7.
The slim housing of the iMac gives it as small a footprint as possible for a device bearing a 27-inch screen, and in use the machine ran nearly silently even when being pushed to the limit. The Mac Pro is equally compact, bearing more resemblance to a pedal bin than a powerhouse computer.
That small, cylindrical frame does still manage to pack a copious amount of ports, which include 6x Thunderbolt 2, 4x USB 3.0, 2x Gigabit Ethernet, and a HDMI 1.4, plus 2x 3.5mm mini jack outputs, one of which is a combined stereo analogue line-out with Toslink digital audio output. The iMac sports a healthy, if slightly smaller, amount of options, with 4x USB 3.0, 2x Thunderbolt 2, 1x Gigabit Ethernet, a 3.5mm headphone/speaker jack, and an SDXC card reader.
One major difference between the computers is that the Mac Pro features a number of options that are surprisingly quick to access and upgrade. Removing the outer shell is a simple operation involving pressing a button and then sliding it off. Once inside you can remove the RAM, which is on the outside of the chassis and held by a couple of clips and the flash-storage is accessed by removing a solitary, standard Phillips screw.
The GPUs and even the CPU itself can also be changed by the user, although you'd need a steady hand and steely nerve to venture into the heart of a machine this expensive. In a teardown on iFixit, the always excellent repair site, the Mac Pro scored 8 out of 10 for reparability, which is one of the highest scores we've seen for an Apple product.
Contrast this with the 5 out of 10 that the iMac with 5K Retina display marked up, and you see how the modular nature of the Pro makes it a great choice for those who like to save money and upgrade machines themselves. This should also prolong the life of the device, as swapping out faulty parts in a few years' time can be done by the user.
Both machines have been out for a little while now, and rumours are already spreading about updates coming this year. On the Mac Pro, the Xeon E5 V3 'Grantley' chips now available and sure to replace the V2 'Romley' versions currently fitted in the workstation machines.
If you're someone who works with highly demanding 3D graphics rendering software, or create and edit lots of effects-heavy video, then the Mac Pro is an obvious choice because of its raw power capabilities. It really is a very impressive machine that looks fantastic, while coming equipped with enough grunt to take on advanced tasks without fear.
The fact that it's so easily upgraded by the user is also a huge benefit when considering your purchase. It's not cheap though, as you might expect, and when you cost in a display (or three) that's worthy of the device you're easily heading towards £3000 or £4000. This makes the Pro a very considered purchase, albeit an excellent one for the right user.
Those looking for a powerful, elegant, all-in-one solution could choose any of the iMac range, but we'd definitely push at least into the 27-inch territory if you're going to use it for professional level tasks. Upgrading the standard hard drives to a 1TB Fusion drive is also a necessity if you want to get the most out of these excellent computers.
Once you've encountered the iMac with 5K display, we're confident that it will prove very difficult to resist. The display is photographic in terms of quality, and we were impressed at how well the machine performed in the vast majority of our tests. It's not as powerful or expandable as the Mac Pro, so keep that very much in mind, but it still remains our favourite Mac of all.