Custom Built 21.5-inch iMac with Intel Core i9 Outperforms 24-inch M1 iMac in Tests

Despite its impressive performance, the new 24-inch iMac powered by the M1 Apple silicon chip, a new project shows that upgrading a previous-generation 21.5-inch ‌‌iMac‌‌ with an Intel Core i9 processor can deliver similar or even better performance.



The new 24-inch ‌iMac‌ is up to 56% faster than the previous generation 21.5-inch ‌iMac‌ with an Intel processor, which it is replacing. The current highest-end 21.5-inch ‌iMac‌ available features an Intel Core i5 processor, but the desktop computer was previously offered with an Intel Core i7.

Now, taking matters into his own hands, Apple YouTuber Luke Miani, in his latest video, decided to outfit the previous generation 21.5-inch ‌iMac‌ with Intel's latest Core i9 processor. A configuration never offered by Apple officially.

Out of the box, the 21.5-inch ‌iMac‌ featured the Intel Core i3 8100 processor, 8GB of RAM, the Radeon Pro 555X graphics card, and 256GB of SSD storage. Miani himself upgrades the ‌iMac‌ to include the Intel Core i9 9900 and 32GB of RAM. All in all, including the upgrades, the 21.5-inch ‌iMac‌ costs $1,250. In contrast, the baseline 24-inch ‌iMac‌ with 8GB of RAM used in the comparison costs $1,299.

In initial tests focused on graphics, such as Geekbench 5, the ‌M1‌ ‌iMac‌ outperforms the custom 21.5-inch ‌iMac‌ with a score of 7,700, compared to the Intel Core i9 scoring 7,400. In Geekbench tests for computing, the ‌M1‌ ‌iMac‌ scores 20,000 compared to the 21.5-inch ‌‌iMac‌‌ featuring the Radeon Pro 555X, receiving a score of 15,789.

In more computing-centric tests, such as Cinebench, the Intel Core i9 scores 9,214, compared to the roughly 7,500 scores for the ‌M1‌ ‌iMac‌. In a Blender render test, the ‌M1‌ ‌iMac‌ takes around six minutes to render a sample project, while the custom-built 21.5-inch ‌iMac‌ completes the render in three minutes and thirty seconds. It's worth noting, however, that Blender on ‌M1‌ is running through Rosetta emulation, meaning there is a slight drawback in performance.

The full video by Miani is a great watch for those interested in possibly upgrading their own ‌iMac‌ with improved RAM, and a more powerful processor.

Popular Stories

imac video apple feature

Apple Unveils First New Products of 2026

Monday January 26, 2026 1:55 pm PST by
Apple today introduced its first two physical products of 2026: a second-generation AirTag and the Black Unity Connection Braided Solo Loop for the Apple Watch. Read our coverage of each announcement to learn more:Apple Unveils New AirTag With Longer Range, Louder Speaker, and More Apple Introduces New Black Unity Apple Watch BandBoth the new AirTag and the Black Unity Connection Braided...
iPhone 5s

iPhone 5s Gets New Software Update 13 Years After Launch

Monday January 26, 2026 3:56 pm PST by
Alongside iOS 26.2.1, Apple today released an updated version of iOS 12 for devices that are still running that operating system update, eight years after the software was first released. iOS 12.5.8 is available for the iPhone 5s and the iPhone 6, meaning Apple is continuing to support these devices for 13 and 12 years after launch, respectively. The iPhone 5s came out in September 2013,...
Second Generation AirTag Feature

Apple Unveils New AirTag With Longer Range, Louder Speaker, and More

Monday January 26, 2026 6:07 am PST by
Apple today introduced the second-generation AirTag, with key features including longer range for tracking items and a louder speaker. For those who are not familiar, the AirTag is a small accessory that you can attach to your backpack, keys, or other items. Then, you can track the location of those items in the Find My app on the iPhone, iPad, Mac, Apple Watch, and iCloud.com. The new...
Apple Creator Studio

Apple's Next Launch is Today

Tuesday January 27, 2026 2:39 pm PST by
Update: Apple Creator Studio is now available. Apple Creator Studio launches this Wednesday, January 28. The all-in-one subscription provides access to the Final Cut Pro, Logic Pro, Pixelmator Pro, Motion, Compressor, and MainStage apps, with U.S. pricing set at $12.99 per month or $129 per year. A subscription to Apple Creator Studio also unlocks "intelligent features" and "premium...
Apple Logo Spotlight

Apple to Launch These 20+ Products This Year

Sunday January 25, 2026 6:02 pm PST by
2026 promises to be yet another busy year for Apple, with the company rumored to be planning more than 20 product announcements over the coming months. Beyond the usual updates to iPhones, iPads, Macs, and Apple Watches, Apple is expected to release its all-new smart home hub, which was reportedly delayed until the more personalized version of Siri is ready. Other unique products rumored for ...

Top Rated Comments

Spanther Avatar
61 months ago
One-off, pimped-out, hand-built Jeep Wrangler Rubicon outperforms factory spec Wrangler Sport in Moab.

News at 11.
Score: 71 Votes (Like | Disagree)
Sebosz Avatar
61 months ago
This brings one interesting thing about these new iMacs - their prices. I know it’s been said many times, but the fact that Apple is offering a 256/8 configuration for $1250 is just absurd. I’ve seen phones with more memory. Or let me put it this way - the money they ask for upgrading these is sick, especially now when nothing in these devices is user-upgradable. It’s just ridiculous.
And before someone says “if you don’t like it don’t buy it” - I’d love to buy one, but I’m not gonna pay 2x more just because I want a 16/1024 configuration.
Score: 54 Votes (Like | Disagree)
macsplusmacs Avatar
61 months ago
This thread is now being drowned out by the noise of the I9's cooling system......
o_O
Score: 45 Votes (Like | Disagree)
fenderbass146 Avatar
61 months ago
okay? Some guy dropped a **** load of money and time to do a mod and it just barely out performs the new entry level
Score: 44 Votes (Like | Disagree)
Andres Cantu Avatar
61 months ago
Lots of salt around the comments. It’s just a project people, not meant to be replicated by the average person who’d just buy the M1.

There’s people out there that appreciate the effort and coolness factor for things like these.
Score: 36 Votes (Like | Disagree)
Rudy69 Avatar
61 months ago

[HEADING=2]Custom Built 21.5-inch iMac with Intel Core i9 Outperforms 24-inch M1 iMac in Tests[/HEADING]
Every single tests in the article was won by the M1 except Cinebench......Who wrote this title?
Score: 30 Votes (Like | Disagree)