The iMac has long been the core of Apple’s desktop lineup, but it hasn’t received any updates since June 2017. Now, however, Apple has quietly updated the 21.5-inch iMac Retina 4K and the 27-inch iMac 5K Retina while keeping prices the same. The bargain-basement non-Retina 21.5-inch iMac remains for sale, but received no changes, making it even less appealing at two years old with a two year old price.

These updates are targeted at improving performance, so you won’t see any changes to the case, screen, or even networking capabilities. But if faster CPUs, GPUs, and memory are what you want, now’s a good time to buy.
The new 21.5-inch iMac boasts speedier 8th-generation Intel quad-core processors and an optional 6-core processor at the top of the line that deliver up to 60% faster performance than previous models. For even greater speed boosts—Apple claims up to 2.4 times faster performance—look to the 27-inch iMac, which now offers 9th-generation 6-core Intel Core i5 processors running at 3.0, 3.1, or 3.7 GHz. If that’s not enough, you can choose an 8-core 3.6 GHz Intel Core i9 processor for the best performance short of an iMac Pro.
By default, both new iMac models have updated versions the previous Radeon Pro graphics chips, but anyone who needs more power can instead choose a blazingly fast Radeon Pro Vega. For the 21.5-inch model, Apple says the Radeon Pro Vega is up to 80% faster; for the 27-inch iMac, it’s up to 50% faster. Though I don’t usually recommend the higher-end graphics options unless your work demands fast image and video processing. They cost way more and in my experience the added heat sometimes shortens the life of the computer.
Note that both iMacs now use 2666 MHz RAM instead of the previous 2400 MHz RAM. It probably won’t make much of a performance difference, but it’s worth keeping the speed in mind if you’re buying RAM separately from the iMac.
For storage, I almost always recommend SSDs. Fusion drives are great if you need massive capacities, but since they are really two drives in one that means double the possibility of a hard drive crash, so especially with a Fusion Drive you must have a Time Machine backup. Whatever you do, don’t buy an iMac with the Serial ATA internal hard drive because it will destroy the performance. Honestly, I’m not even sure why Apple offers this option. It will be slow from day-one, never mind in 5 to 7 years. SSDs generally increase the speed of your computer by 2 to 5 times especially in application load time, which can add 2 to 3 years to the useful life of the computer.
Choosing your new iMac configuration
I never, ever recommend getting the stock configuration, especially if you are getting the smaller 4k 21″ model. They are hard to impossible to upgrade so you need to get the computer you want for the next 7 to 10 years, not the computer that works for you right now.
- Processor: Of course more numbers mean your computer will go faster. That doesn’t mean double the number means double the speed; there are other contributing factors. Most people will not notice the processor speed making a difference unless they do heavy computing like video editing or Photoshop with huge files. Get what you can afford, though quite honestly for most home and office users the slower processors are more than enough.
- Memory (RAM): The basic configuration is 8 GB, which is probably fine for most people at the moment. But in the future it might not be enough since software often gets more complex and demands more of the computer. So I recommend getting 16 GB. The smaller 4k iMac cannot be upgraded, so it’s especially important on that model. The larger 5k iMac can be easily upgraded by opening a panel on the back, so that’s not too important up front, but if it’s slow in the future the first thing I would do would be to add some additional chips.
- Graphics: Like the processor, more doesn’t always mean better. Unless you play games or edit video, a higher-end graphics chip probably won’t make an ounce of difference. Most home and office users can go with the basics here.
- Storage: Always get an SSD if you can afford it. It will greatly increase the speed, reliability, and life of your computer. In general I recommend looking at your current storage usage and getting twice that for future growth. You can see your current storage usage in the Apple menu > About this Mac > Storage. This cannot be easily upgraded in the future. Fusion drives are much faster than plain drives, though they are also less reliable because if either of the two drives goes the whole thing does.
- Mouse and Keyboard: if ordering from Apple you have an option of the mouse or trackpad. Get whatever you are more comfortable with. The keyboard, however, has a hidden choice. By default you will get the keyboard that does not have a number pad on the side, much like a laptop keyboard. However, if you do any number entry, the numeric keypad will be well worth the extra $30. Click the “Change” button under the keyboard section and choose the numeric keypad.
For those looking for the ultimate power in an iMac Pro, Apple also quietly added options for 256 GB of RAM (for a whopping $5200) and a Radeon Pro Vega 64X GPU ($700) while simultaneously dropping the prices on some other RAM and storage options.