The iMac Pro is now Apple's biggest, baddest desktop computer. With up to 18 cores on a Xeon W processor, the all-in-one machine can power fast single-threaded tasks and monster multi-threaded workflows.
As such, it's no surprise that Apple also offers a massive amount of RAM for the machine: The baseline iMac Pro ships with 32GB 2666MHz DDR4 ECC RAM (a true monster sentence of acronyms), but you can also upgrade to 64GB or 128GB when you configure your computer.
This is also the only configuration you can upgrade after the fact — though, due to the complications of adding components to such a small package, currently you're restricted to having it done at an Apple Store or Authorized Reseller. (The days of opening up your iMac yourself and swapping out RAM chips are gone.)
Which configuration should you buy with an iMac Pro? Read on.
Who should get 32GB of RAM in their iMac Pro?
As mentioned above, 32GB comes standard in the $4999, 8-core iMac Pro configuration. It's likely (though not confirmed) that we're looking at four 8GB DDR4 sticks, given the build of the Xeon W processor.
It's a good starting configuration for the machine, and allows Apple to offer it without completely destroying prospective buyers' bank accounts. 32GB will suit you for most mid-level single-threaded and multithreaded tasks, though you're always going to get more performance for your multithreaded tasks as you upgrade.
That said, the first upgrade point — to 64GB — is an $800 jump. That's the same cost as upgrading from the 8-core to 10-core processor; in the long run, if you have to choose between upgrading one of those, you might be better suited in upgrading the processor first, then ordering the RAM at a later date.
If you can't afford the RAM upgrade at launch, you can get along just fine for most tasks with 32GB. If you can afford to sink some money into your purchase, however, opt for 64GB.
Who should get 64GB of RAM in their iMac Pro?
64GB will be the RAM sweet spot for most iMac Pro users: By doubling the initial configuration and supplying four 16GB sticks, you'll get a noticeable improvement on an 8- or 10-core machine, and be able to keep up with the processing power of a 14-core model.
If you plan on doing intermediate to advanced video editing, 2D or basic 3D graphics work, development, or other mid-range pro tasks, 64GB of RAM should suit you nicely.
If you're working on more advanced tasks (VR development, 3D FX, or massive multithreaded computing), you've likely already upgraded to the 14- or 18-core model; as such, you should similarly consider upgrading to 128GB of RAM for your iMac Pro's best performance.
Who should get 128GB of RAM in their iMac Pro?
By consumer standards, 128GB is a truly ridiculous amount of RAM. No Mac offers the configuration aside from the iMac Pro, and for good reason: The only reason to have this much memory is when you're pairing it with a powerhouse processor like the 14- or 18-core Xeon W. If you plan on pushing your iMac Pro to its limits, you're going to want to upgrade its RAM alongside processor and video card upgrades. This will allow you to work within more projects and apps simultaneously; it'll also afford gigantic data sets the memory they need to properly compute in time.
Don't get 128GB of RAM unless you're opting for the 14- or 18-core processor, or you think you'll truly push the Apple's 10-core to its max: Consider 64GB instead.
What RAM would you get in your iMac Pro?
If you're planning on buying an iMac Pro, which RAM configuration would you choose? Let us know in the comments.