If you really need 256GB of RAM inside your iMac Pro, you’d better make sure you buy it that way from Apple. It seems it is impossible for owners to upgrade to this configuration after purchasing their machines — even if they have the latest model.
Apple introduced the 256GB of RAM option to the iMac Pro last week. It’s a costly configuration, with the RAM alone priced at $5,200 on top of the iMac Pro’s base price of $4,999. But don’t think about trying to get a cheaper upgrade after you’ve received the new all-in-one.
New Apple documentation suggests there is no way for machines that didn’t ship with 256GB of RAM to be maxed-out later.
256GB RAM not an upgrade option
When you opt for 256GB of storage in the iMac Pro, you get four 64GB memory modules. Only machines that are ordered with 256GB of RAM are designed to hold those modules. Those that shipped with 128GB or less simply cannot hold 256GB.
Not even Apple can max-out your iMac Pro after you’ve purchased it.
That’s according to an internal document distributed to Apple Stores and Apple Authorized Service Providers, seen by MacRumors. “In other words, purchasing an iMac Pro with 256GB of RAM will only be possible via the CTO option on Apple’s online store,” it explains.
iMac is more flexible
Fortunately, things are different for the standard iMac. OWC has confirmed that the new 27-inch model, which also debuted last week, can be upgraded to 128GB of RAM. That’s despite Apple offering a maximum of 64GB through its own retail channels.