21.5–inch iMac (Early 2019)
Apple’s big desktop Mac gets hot new processors — but retains some old tech
Display 5120x2880–pixel Retina display Processor 3.6GHz Intel Core i9 Memory 16GB Storage 512GB SSD Graphics AMD Radeon Pro Vega 48 8GB Connectivity 2x Thunderbolt 3 ports, 4x USB–A ports, SDXC card reader, Gigabit Ethernet, 3.5mm headphone jack, 802.11ac Wi–Fi, Bluetooth 4.2
Almost two years since its last update, the iMac returns with refreshed components, including ninth–gen Intel Core i9 processors and AMD Radeon Vega 48 graphics. Those optional high–end parts contribute to the big price tag at the top of this review, which is for the souped–up spec that we tested.
You might be tempted to rush into looking at the new Intel and graphics processors’ capabilities to help decide which new iMac to buy, but let’s first talk about the one component that every buyer ought to upgrade for performance reasons: storage. All 27– inch iMacs come with a Fusion Drive: 1TB in the base and mid–range models, 2TB in the top one. This tech is meant to offer some of the benefit of an SSD’s speed without sacrificing the large capacity of a hard disk.
Our tests showed that the latest Fusion Drives sometimes — too often, in fact — deliver disappointing performance compared to the specifications Apple used back in 2012. There are specific details on what’s going on in the box on page 44, but the one thing to take away from our testing is that you would be sensible to pay extra for a pure SSD so that you aren’t left frustrated by Fusion Drive performance.
On each of the three stock 27–inch iMacs, the least costly SSD upgrade adds $100 to the price and means reducing the internal storage to 25 per cent of normal. Buy the largest capacity within your budget and that fits your needs.
You may need to buy an external hard drive to give you enough space to archive files you won’t need soon. You’ll then have to take on the overhead of organizing things manually, but day–to–day your Mac will enjoy the responsiveness it and you deserve in 2019. The core question All three stock configurations are equipped with a six–core processor. In the $1,799 and $1,999 models, you get an eighth–gen Intel Core i5, both featuring Intel’s Turbo Boost tech, which can raise the clock speed of active cores when some of the total number are idle.
The top 27–inch iMac is a slightly different proposition to all other iMacs because it has a ninth–gen processor, also from the Core i5 family. However, the iMac we tested was an even higher spec: a Core i9 processor. This option is available only on the middle and top 27–inch iMacs. Brace yourself, as it bumps up the cost by $500 on the former and $400 on the latter. So, the least you’ll pay for the capability that these eight cores — and 16 processing threads — can deliver is $2,499.
One of the reasons we test using the free video transcoding app HandBrake is that it tends to make full — or close to full — use of however many processing cores are available to it. Our traditional test for this is to encode a roughly half–hour video to H.264 format. The 16 processing threads available on our 27–inch iMac tear through this test with ease. So, last year we began to test processor capability by also encoding a 57–minute video to the HEVC (or H.265) format. This is more demanding for a device to handle. The 27–inch iMac’s Core i9 took 43 minutes and 4 seconds to finish the task. It’s worth noting that it’s the only new Mac that we’ve tested in recent months that has been able to complete the job in less time than the video’s duration.
In contrast, the quad–core i7 in our 2018 13–inch MacBook Pro took 1 hour