REVIEW OF THE MONTH Apple iMac Pro
The iMac Pro delivers power, practicality and beauty in one minimalist package: it’s the most powerful all-in-one ever made
We’re spoilt for choice when it comes to new hardware this month, whether it’s the Samsung Galaxy S9 ( see p62), Dell XPS 13 ( p54) or the latest Raspberry Pi ( p58). But it’s the iMac Pro that takes pride of place. We’ve accused Apple of ignoring creative professionals in its relentless pursuit of the affluent mainstream, and that criticism still holds: four years between major hardware releases isn’t good enough. However, only the most hard-hearted of critics could fail to be impressed by the amount of graphical and CPU- based power inside this new release. Whether it’s worth the asking price is quite another matter.
Workstations. Not a product category one would typically associate with the word “gorgeous” . Or “beautiful”, or “stunning”. Yet all three trip off the tongue in the Apple iMac Pro wordassociation game.
To be fair, the same could be said of any iMac that Apple has produced in the past few years – and there’s very little difference, from a physical perspective at least, between the iMac Pro and the 27in 5K iMac launched four years ago.
That’s because the iMac Pro doesn’t need a redesign. It remains the epitome of cool sophistication and minimalism. Its clean lines, smoothly curved rear and low profile Magic Mouse and keyboard look fabulous on any desk, especially the kind of desks favoured by Bauhaus designers with rimless glasses.
Despite this, Apple has found a couple of small ways to improve on the practicalities. On the rear are now four USB-C ports – all Thunderbolt 3 enabled – in addition to four USB Type-A ports, a networking port capable of supporting 10GbE, and an SD card slot.
So what separates the iMac Pro from its far cheaper siblings – aside from the fetching Space Grey finish, matching moody peripherals and shock-treatment price? Barring a couple of small improvements, including the ability to VESA mount the iMac Pro to a stand of your choice, it’s all about what’s inside.
What’s inside counts
The iMac Pro’s components are drastically different from what you’ll find in a regular iMac 27in, even the top-line 5K model. This starts with the processor: instead of Intel’s consumer-focused Core chips, here Apple offers an array of Intel Xeon W processors.
Buried deep in the heart of the model on review is a workstationgrade eight-core, 16-thread Xeon W-2140B processor running at 3.2GHz, but you can upgrade that to a 3GHz 10-core, 2.5GHz 14-core or a 4.3GHz 18-core chip.
Our review machine has a mere 32GB of 2,666MHz DDR4 of ECC RAM, but again you can up that to 64GB or 128GB. The storage subsystem is equally impressive, with an incredibly quick 1TB SSD, upgradable at the point of purchase to 2TB or 4TB of SSD storage. Plus, there’s a choice of AMD Radeon Pro Vega 56 or Vega 64 graphics; the former with 8GB of HBM2 memory, the latter with 16GB.
For context, the model I have on the desk in front of me is the cheapest Apple makes, and that costs £4,899. If you want the 4.3GHz 18-core machine with 128GB of RAM, a 4TB SSD and a Radeon Pro Vega 64 then prepare to part with £12,279.
Ludicrous power
In all its guises, this is a ludicrously powerful machine. It’s intended to deal with power-hungry tasks such as 8K video editing and rendering, complex music creation and mixing, CAD/CAM, 3D visualisation and design, even VR-driven creation – the sorts of tasks that bring even the most powerful consumer systems to their knees.
You don’t need an iMac Pro if you’re editing basic 1080p clips or even putting together straightforward 4K video editing projects. Nor is this the machine for photo editing or illustration – you’d have to be working on files with hundreds of layers and filters for it to be worth the extra outlay. But, if your video projects are long and complex, you’re working with multiple layer effects, or you deal with complex 3D models on a regular basis, the extra power will certainly come in handy. As will the iMac Pro’s ECC RAM, which should make it slightly less likely to crash – a potential life-saver if you’re going to be using the machine for long renders. And, as Apple is keen to point out, creative professionals will increasingly be working on 360-degree video and VR content in the future, both of which place a huge strain on computer hardware.
How does it perform? That will depend largely on the sorts of tasks you put it to, but in our suite of benchmarks, the iMac Pro puts clear water between itself and the regular 5K iMac.
Our in-house benchmarks carry out a series of demanding image and video conversion tests, then tops these basic tasks with a multitasking test. An overall score of 281 makes it more than twice as fast as the 27in iMac 5K we reviewed, which is what you’d expect from a machine that’s more than double the price.
I also ran a series of workstationcentric benchmarks on the iMac Pro, including Cinebench and a down conversion of a 4K movie file to 1080p – the sort of process users of the iMac Pro would be likely to perform on a fairly regular basis – and none of these threw up any issues.
Compared with the selection of similarly equipped desktop
“The iMac Pro is designed for the sort of tasks that bring even the most powerful consumer systems to their knees”
“If all you want is display connectivity, you’re better off buying a workstation PC in a big boring box”
workstations in our group test ( see issue 281, p76), this iMac Pro stacks up competitively. It’s also worth pointing out that throughout the testing, the iMac Pro remained responsive, quiet and thermally stable.
Take the 4K down conversion. Using Adobe Premiere’s High Quality 1080p preset, the iMac Pro completed this with OpenCL hardware acceleration enabled in 405 seconds and with Metal hardware acceleration in 400 seconds. That’s not quite as quick as the £2,500 big box workstations from that Labs test, or indeed the Dell workstation opposite, but bear in mind those are housed in big, bulky boxes.
In the Luxmark Hotel Lobby GPU test, it fared better, beating all but the super-expensive £4,650-plus machines with a score of 3,577, while a CPU score of 1,680 in Cinebench 15 places it mid-table once again.
The iMac Pro’s stellar performance continues through to storage, and here speed is more competitive. The 1TB NVMe SSD inside the iMac Pro is a commanding beast. In fact, it’s made up of two drives in a sort-of-RAID configuration and it kicks out impressive numbers. Sequential write speeds hit 3,003MB/sec and sequential reads of 2,487MB/sec in the BlackMagic disk test, which is around three times as fast as the 512GB SSD in the Mac Pro I reviewed way back in 2014.
What’s more, it achieves this with full AES disk encryption in place – hardware-accelerated by the iMac Pro’s new Apple T2 security chip. Not everyone needs such a high level of security, of course, but for those that do, it’s good to see that its application doesn’t have a negative impact on performance.
Graphics performance doesn’t quite reveal the same advantage. Tested using Unigine’s Heaven benchmark, the iMac Pro reached 48fps at 2,560 x 1,440 resolution and medium detail, which is only a slight improvement over the 5K iMac’s result. That’s still a strong score and it’s worth remembering that, if you do need more graphical grunt – for GPGPU acceleration for instance – you’ll shortly be able to hook up external graphics cards via one of the iMac Pro’s four Thunderbolt 3 ports.
Sweet display
Right now, the Thunderbolt 3 connections on the rear of the iMac Pro can be used to hook up two extra 5K displays in addition to the 27in display already in place.
But you’re not going to buy an iMac Pro for its display connectivity. If that’s all you want, you’re better off buying a workstation PC in a big, boring box from the likes of Dell, HP or Scan. You’ll receive a similar level of specification for much less than this, and can then specify a monitor of your choice.
However, if you want a monitor that matches the iMac Pro’s for quality, you’re looking at a total spend that’s not far off that of the equivalent iMac Pro. The
difference is, of course, that you don’t have to buy the monitor again if you want to upgrade your processor, graphics card or any other component. Beautiful though the iMac Pro is, practical and easy to upgrade it ain’t.
But, as I’ve come to expect over the years, the screen attached to the iMac Pro is an absolute corker. Out of the box, the iMac’s 5K IPS panel comes tuned to the DCI-P3 colour space. When I tested it with our in-house colorimeter, it successfully reproduced 98.9% of the DCI-P3 colour space - a superb result. Brightness and contrast are excellent, too, reaching a searing 551cd/m2 and a contrast ratio of 1,044:1.
The only complaint you could possibly have about the iMac Pro’s display is the broad bezel. In a world where smartphone, laptop and tablet manufacturers are falling over themselves to fill the fronts of their devices with nothing but screen, this is one area where the iMac Pro looks behind the times.
The gloss finish isn’t ideal if you work in an office with overhead strip-lighting, although in the time I was using the machine, the iMac Pro’s anti-reflective coating did a good job of keeping distractions to a minimum.
Pros and cons
There’s no question that Apple’s iMac Pro is a hugely impressive machine. Its processing power, storage subsystem and connectivity are fantastic, and it isn’t even badly overpriced when you take into account the fact that it’s all attached to a professional-grade DCI-P3 calibrated 27in 5K monitor.
Of course, you do get more bang for your buck if you go with separates, especially as you bump up the specifications for the iMac Pro. That was always going to be the case. Note the limited warranty too.
However, as an elegant, powerful all-in-one for the modern digital creative who’s pushed for space, there’s nothing else like the Apple iMac Pro on the market. It’s powerful, practical, flexible and capable. The most powerful iMac Apple has ever made is also the best all-in-one ever made.
SPECIFICATIONS Octa-core 3.2GHz Xeon W-2140B processor AMD Radeon Pro Vega 56 graphics with 8GB of HB2M memory 32GB 2,666MHz DDR4 ECC memory 1TB SSD 27in 5,120 x 2,880 Retina 5K IPS display SDXC card slot 4 x USB 3 4 x Thunderbolt 3/USB-C 10 Gigabit Ethernet 802.11ac Wi-Fi Bluetooth 4.2 FaceTime HD camera macOS Sierra Magic Mouse 2 Magic Keyboard 650 x 203 x 516mm (WDH) 9.7kg 1yr RTB warranty