It's been over a year since Apple refreshed its iMac lineup with updated hardware and added Thunderbolt 3. After long-term daily use of the computer in that period, now is probably a good time to reflect on the iMac, and how we feel about the machine a year after release.
The iMac 5K has been AppleInsider's main video editing machine since it was released. To make it more useful for the workload, we opted for the highest-specification model with 8 gigabytes of RAM and a 512-gigabyte SSD, a setup that was cheaper than the new top-spec i9 MacBook Pro released in July.
The iMac 5K is the only new Mac that allows you to easily add third-party RAM. Taking advantage of this, we added another 32 gigabytes, and now it is equipped with 40 gigabytes for only $3,000 — $300 less than the 32-gigabyte model from Apple.
The best comparison to make with it is against the iMac Pro, the next tier up in terms of specification. For $2,000 more in terms of cost, you'd get an 8-core processor, 32 gigabytes of RAM and 1 terabyte of SSD storage in the base model.
It may seem worth it to go with that over the iMac 5K because it should easily outperform the iMac 5K, right?
Before we get into performance testing, let's discuss what we like and don't like about the iMac 5K.
The design of the iMac is iconic and high quality, but it's been 6 years since the last redesign, and the large chin is starting to look a bit dated. The 5K display, however, remains amazing, due to its high detail, brightness, and color accuracy.
We love the large amount of ports in the back, especially the Thunderbolt 3 ports, which we use to connect a 40TB storage area network device that can be accessed by two Macs at the same time, with the high bandwidth offered by Thunderbolt 3 providing very fast transfers to both desktops.
The keyboard and mouse supplied with the iMac are great, with few Bluetooth connection issues since buying it. The batteries stay charged for weeks, and they recharge incredibly quickly as well, which is handy since you have to flip the mouse over to do so.
Onto the internals, the 2017 iMac 5K switched over to Intel's Kaby Lake processors, which added hardware acceleration for the HEVC codec, the current standard for 4K video streaming.
It also introduced desktop-class graphics chips for the first time in years, and even the cheaper Radeon Pro 570 is substantially faster than the best graphics options in older models from 2015.
Our iMac 5K has the Radeon Pro 580, which is actually the same graphics chip that came in the new Blackmagic eGPU, which is mostly marketed towards MacBook Pro users. We have previously compared the eGPU-equipped Core i9 2018 MacBook Pro with the 2017 5K iMac and the iMac Pro, and found that, even with the extra power of the eGPU, it isn't enough to beat our iMac 5K.
Starting with Geekbench 4's CPU test, the iMac 5K gets the best single-core score across the models we tested, but also the worst multi-core score, mainly due to the differences in the amount of cores. Under Geekbench 4's graphics test, the iMac Pro is the clear winner.
In Cinebench R15, the iMac 5K is not far from the 2018 i9 MacBook Pro in its results, and that's mostly because of the thermal design of the MacBook Pro. The iMac Pro simply destroyed both machines in the test.
We also looked at video gaming performance with Unigen's Heaven Benchmark. The iMac Pro did extremely well here, and the iMac 5K easily did better than the MacBook Pro.
Onto the real world tests, the Lightroom export test showed the iMac 5K sits between the i9 MacBook Pro and the iMac Pro in the results.
The Final Cut Pro X video editing tests started with Bruce X, with the iMac 5K actually scoring incredibly close to the iMac Pro. A 20 second 4K clip stabilization test surprised us, as the iMac 5K was ahead of the other Mac systems by a huge amount.
The i9 MacBook Pro destroyed the iMac 5K in the HEVC to HEVC export test, even topping the iMac Pro, because the 8th-gen processor is using the latest QuickSync encoding and decoding technology. The iMac Pro's Xeon CPU doesn't have integrated graphics to enable QuickSync, but the raw power allows it to still get the job done quickly.
Moving on to a 5min 4K export, the iMac Pro was actually the slowest in this test, again due to the lack of QuickSync. The MacBook Pro was slower than the iMac 5K, due to the thermal throttling of the processor and the less powerful graphics.
For our Canon RAW 60 frames per second test, the iMac 5K was right behind the iMac Pro, while the MacBook Pro was extremely slow. We also tested timeline smoothness during this test, and the iMac Pro was the only one that played it back at the full 60 frames per second.
Overall, the top-spec i9 MacBook Pro performs worse than the 2017 iMac 5K in almost all of the tests we ran, which is completely unexpected based off the spec sheet.
We were also surprised at how close the iMac 5K performed compared to the iMac Pro, even beating it in some tests thanks to QuickSync.
The one-year opinion
After working in video editing full-time on the iMac 5K since it was released, I can tell you it's really up to the job. I've used a top-spec 2016 15-inch MacBook Pro a few times, and it paled in comparison. We shoot and edit everything in 4K and perform a lot of stabilization, and since this processes almost twice as fast on this iMac 5K compared to the MacBook Pro, the time savings really add up throughout the day.
We export everything in 4K as well, which again is faster on the iMac 5K, so this machine really is the best bang for the buck for this particular situation.
On the negative side, the fans spin up and get loud when exporting longer 4K videos. I personally prefer using Google Chrome as a browser, and even with 40GB of RAM, the fans can sometimes kick up really loud when I'm researching and opening a bunch of tabs at once. This is more on Google than on Apple's hardware, though.
Apple recently added HDR editing support to Final Cut Pro in the 10.14 update, but of course, there's still no HDR display in any Mac device. This hints that Apple will either be working with a company like LG to bring us a new HDR display, or Apple will do it themselves in the next iMac or iMac Pro, or maybe even the rumored Apple Cinema Display, but that remains to be seen.
Overall, the 2017 top-spec iMac 5K is one of the best performing Macs ever made, and in our opinion, the best bang-for-your-buck Mac in terms of performance.