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.

imac pro white background
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 Forum: iMac

Popular Stories

Apple Announces Special Event in New York Feature

Apple Announces Special Event in New York, London, and Shanghai on March 4

Monday February 16, 2026 6:05 am PST by
Apple today announced a "special Apple Experience" in New York, London, and Shanghai, taking place on March 4, 2026 at 9:00am ET. Apple invited select members of the media to the event in three major cities around the world. It is simply described as a "special Apple Experience," and there is no further information about what it may entail. The invitation features a 3D Apple logo design...
M3 iPad Air

Apple's Next Two Products Are Coming Soon

Thursday February 12, 2026 11:17 am PST by
Apple plans to release an iPhone 17e and an iPad Air with an M4 chip "in the coming weeks," according to the latest word from Bloomberg's Mark Gurman. "Apple retail employees say that inventory of the iPhone 16e has basically dried out and the iPad Air is seeing shortages as well," said Gurman. "I've been expecting new versions of both (iPhone 17e and M4 iPad Air) in the coming weeks."...
Apple Announces Special Event in New York Feature 1

Apple Event on March 4: Here's What to Expect

Tuesday February 17, 2026 8:08 am PST by
Apple on Monday invited selected journalists and content creators to a "special Apple Experience" on Wednesday, March 4 in New York, London, and Shanghai. At an Apple Experience, attendees are typically given the opportunity to try out Apple's latest hardware or software. Following the launch of Apple Creator Studio last month, for example, some content creators attended an Apple Experience...
iphone 17 pro dark blue 1

Gurman: iPhone 18 Pro Could Be Underwhelming

Monday February 16, 2026 4:24 am PST by
Apple's upcoming iPhone 18 Pro and iPhone 18 Pro Max models "won't be a big update," according to Bloomberg's Mark Gurman. In the latest edition of his "Power On" newsletter, Gurman said that the iPhone 18 Pro models will "represent minor tweaks from last year's iPhone 17 Pro and 17 Pro Max." He compared the upgrade to Apple's past practice of appending the letter "S" to its more minor...
Coffee Burgundy and Purple iPhone 18 Pro Mock

Five iPhone 18 Pro Features Revealed in New Report

Friday February 13, 2026 8:43 am PST by
While the iPhone 18 Pro and iPhone 18 Pro Max are still seven months away, an analyst has revealed five new features the devices will allegedly have. Rumored color options for the iPhone 18 Pro models In a research note with investment firm GF Securities on Thursday, analyst Jeff Pu outlined the following upgrades for the iPhone 18 Pro models: Smaller Dynamic Island: It has been rumored...

Top Rated Comments

PinkyMacGodess Avatar
90 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.

EDIT: My point is that 'Pro's' need flexibility. If there is no physical way to upgrade the system, then it's either buy top of the line, or look elsewhere. The closed agenda has to be costing them some users, one would think...
Score: 36 Votes (Like | Disagree)
90 months ago
Surprise! Who'd have thought Apple would pull more of this ****?!
Score: 29 Votes (Like | Disagree)
falainber Avatar
90 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.
Score: 27 Votes (Like | Disagree)
PinkyMacGodess Avatar
90 months ago
"Pro" stands for "proficient"
Or 'PROfit' as people have to upgrade to get more memory?
Score: 22 Votes (Like | Disagree)
Plutonius Avatar
90 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.
Score: 21 Votes (Like | Disagree)
BaccaBossMC Avatar
90 months ago
Oh no! Limited to a plebian 128GB of RAM on the most RAM-efficient OS available! What ever will we do? /s
Score: 17 Votes (Like | Disagree)