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Upgrading an iMac Pro to 256GB of RAM Only Possible at Time of Purchase [Updated]

Update: Despite what Apple's internal document stated, OWC has released an aftermarket 256GB memory upgrade kit for the iMac Pro for $2,499.



Last week, Apple added a 256GB RAM configure-to-order option for the iMac Pro. Unfortunately, if you already purchased an iMac Pro with 128GB of RAM or less, upgrading to 256GB does not appear to be possible.


The new 256GB RAM option consists of four 64GB memory modules, and in an internal document distributed to Apple Stores and Apple Authorized Service Providers, Apple states that the new configured-to-order ‌iMac Pro‌ is the only model designed to work with those 64GB memory DIMMs. No reason is provided.

This information suggests that Apple Authorized Service Providers will not be able to upgrade an ‌iMac Pro‌ to 256GB of RAM, nor will third-parties like OWC. In other words, purchasing an ‌iMac Pro‌ with 256GB of RAM will only be possible via the CTO option on Apple's online store during the checkout process.

256GB of RAM is a $5,200 upgrade option on Apple's online store, in addition to the ‌iMac Pro‌'s base $4,999 price.

The standard iMac is a bit more fortunate, as OWC has confirmed that the new 27-inch models released last week can be upgraded with up to 128GB of RAM, despite maxing out at 64GB on Apple's online store.

Related Roundup: iMac Pro
Buyer's Guide: iMac Pro (Neutral)

Top Rated Comments

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7 months ago
Should Apple retire the 'Pro' name. It's obvious they can't deliver. Sad, really... And I cling to my Macpro4,1 hoping it lasts a few more years.
Rating: 37 Votes
7 months ago
Surprise! Who'd have thought Apple would pull more of this ****?!
Rating: 29 Votes
7 months ago

Oh no! Limited to a plebian 128GB of RAM on the most RAM-efficient OS available! What ever will we do? /s

In desktops, RAM is mostly needed for apps not OS.
Rating: 26 Votes
7 months ago

"Pro" stands for "proficient"


Or 'PROfit' as people have to upgrade to get more memory?
Rating: 22 Votes
7 months ago
I'm not sure what professionals are in the market for an iMac Pro if they need 256 Gig. Until Apple comes out with a revised Mac Pro, I would probably looking at non-Apple solution for a lot less money.
Rating: 21 Votes
7 months ago
Oh no! Limited to a plebian 128GB of RAM on the most RAM-efficient OS available! What ever will we do? /s
Rating: 17 Votes
7 months ago
I’ve had my 18-core iMac Pro w/ 128GB of RAM for a year now and I love it. For those questioning why someone would ever need 256GB of RAM, well, you obviously don’t need it. And that’s okay. But there are users out there that can benefit from large amounts of RAM.
Rating: 12 Votes
7 months ago
I still don’t see why a professional machine is made such that RAM/storage is inaccessible/soldered. Garbage engineering and greed is the only explanation.
Rating: 12 Votes
7 months ago

If you need > 256GB of RAM, you don't need more RAM. You need a new workflow/process/application architecture. At some point, if you need ~60GB/s throughput for that much data, you probably need to consider a distributed and scalable version of whatever it is that you're doing.


Nope. Scientific computing where most of the problems are solving a large matrix. You have to solve the whole thing at once and it has to sit in memory at the same time.

Scalable Xeon gives you 128 GB/socket of memory bandwidth. Put that in a 8 socket system and you got 1 TB/s. The moment you to a different system, the best you can get with Inifiniband is 200 gigabit, 64% of a single socket. Plus latency is up by at least a factor of 10.
Rating: 12 Votes
7 months ago
This is not new for Apple. Check out the MacTracker - there are decades of Macs that had "official" RAM capacities and "unofficial" RAM capacities. I'd be willing to bet that an iMac Pro built last year would still accept 256GB of RAM. Getting to it is another matter since it's sealed behind adhesive and probably two dozen fasteners.
[doublepost=1553784574][/doublepost]

Or anything on Android. ;)


What does Android have to do with the iMac Pro?
Rating: 11 Votes

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