Custom Built 21.5-inch iMac with Intel Core i9 Outperforms 24-inch M1 iMac in Tests - MacRumorsOpen MenuShow RoundupsShow Forums menuVisit ForumsOpen Sidebar
Skip to Content

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

duo aquarium

More Fun iPhone Duo Apps: 30 New Picks to Try

Friday November 6, 2026 3:27 pm PST by
When the iPhone Duo launched, we shared a list of some of the fun apps developers created for the new form factor. Two weeks out, developers are continuing to come up with fresh ideas, so we thought we'd share some of our favorites. Games Marbles Unhinged ($2.99) - Marbles Unhinged is a marble maze designed for the Duo. When you fold it, the floor turns into a ramp. If you stand the top...
apple pro tell logo

Apple Launching Five New Products Today

Thursday November 5, 2026 12:59 am PST by
Apple is launching five new products on Friday, November 6, following pre-orders that opened last week, including its first touchscreen MacBook Pro models. The following new products will be available from today: iPad mini with OLED display and A20 Pro chip iMac with M6 chip 14-inch MacBook Pro with M6 chip 14-inch MacBook Pro with OLED touchscreen 16-inch MacBook Pro with OLED...
iOS 28 AI

Apple Taking New Approach to Developing iOS 28 and macOS 28

Sunday November 8, 2026 7:42 am PST by
Apple has made a change to its development process for iOS 28, macOS 28, and corresponding software updates, according to Bloomberg's Mark Gurman. In his Power On newsletter today, he said Apple separates development of each year's new operating systems into three major stages. Typically, he said each stage consists of four weeks of coding followed by a four-week "convergence" period where...

Top Rated Comments

Spanther Avatar
71 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
71 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
71 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
71 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
71 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
71 months ago

Custom Built 21.5-inch iMac with Intel Core i9 Outperforms 24-inch M1 iMac in Tests
Every single tests in the article was won by the M1 except Cinebench......Who wrote this title?
Score: 30 Votes (Like | Disagree)
Latest Stories
Apple Store Subscription Sign-Up Controversy Exposed
Apple Store Subscription Sign-Up Controversy Exposed
3 hours ago
Siri AI Rumored to Become 'More Like an Agent' as Early as Next Year
Siri AI Rumored to Become 'More Like an Agent' as Early as Next Year
13 hours ago
Apple Taking New Approach to Developing iOS 28 and macOS 28
Apple Taking New Approach to Developing iOS 28 and macOS 28
15 hours ago
Early Apple Black Friday Deals on Apple Watch, MacBook Air, and More
Early Apple Black Friday Deals on Apple Watch, MacBook Air, and More
1 day ago
'Backglow' Lets You Customize New MacBook Pro's Glowing Apple Logo
'Backglow' Lets You Customize New MacBook Pro's Glowing Apple Logo
1 day ago
Top Stories: Apple Product Launches, iOS 27.3 Beta, and More
Top Stories: Apple Product Launches, iOS 27.3 Beta, and More
2 days ago
More Fun iPhone Duo Apps: 30 New Picks to Try
More Fun iPhone Duo Apps: 30 New Picks to Try
2 days ago
Hands-On With Apple's New OLED Touchscreen MacBook Pro
Hands-On With Apple's New OLED Touchscreen MacBook Pro
2 days ago
Apple Store With All-New Design Opening Soon in Southern California
Apple Store With All-New Design Opening Soon in Southern California
2 days ago
Control the Glowing Apple Logo on Your New MacBook Pro
Control the Glowing Apple Logo on Your New MacBook Pro
2 days ago
Apple Shares New 'Apple Card: Apply and Use in Minutes' Ad
Apple Shares New 'Apple Card: Apply and Use in Minutes' Ad
3 days ago
Apple Says More Than 100,000 Apps Optimized for iPhone Duo, Here's What's Still Missing
Apple Says More Than 100,000 Apps Optimized for iPhone Duo, Here's What's Still Missing
3 days ago
Early Black Friday Deals Kickoff With Steep Discounts on Apple Watch Ultras and More
Early Black Friday Deals Kickoff With Steep Discounts on Apple Watch Ultras and More
3 days ago
The MacRumors Show: iOS 27.3 Looks Like a Huge Update
The MacRumors Show: iOS 27.3 Looks Like a Huge Update
3 days ago
Best Buy's Black Friday Event Begins With Sitewide Savings on Apple, TVs, More
Best Buy's Black Friday Event Begins With Sitewide Savings on Apple, TVs, More
3 days ago
Apple Releasing Yet Another Two New Products Next Week
Apple Releasing Yet Another Two New Products Next Week
3 days ago
MacBook Air Drops to Lowest Price in Months With Amazon's $250 Discount
MacBook Air Drops to Lowest Price in Months With Amazon's $250 Discount
3 days ago
Apple Rumored to Drop the iPhone's Action Button Next Year
Apple Rumored to Drop the iPhone's Action Button Next Year
3 days ago
Apple's Extended Return Policy Now in Effect for 2026 Holiday Season
Apple's Extended Return Policy Now in Effect for 2026 Holiday Season
3 days ago
Apple Music Classical Updated With New Icon and Refreshed Design
Apple Music Classical Updated With New Icon and Refreshed Design
3 days ago
OLED iPad Mini, M6 iMac, and New MacBook Pros Available From Today
OLED iPad Mini, M6 iMac, and New MacBook Pros Available From Today
3 days ago
Apple Surveys iPhone Duo Buyers About Crease and Camera
Apple Surveys iPhone Duo Buyers About Crease and Camera
3 days ago
Apple's First Touchscreen Mac is Now Arriving to Customers
Apple's First Touchscreen Mac is Now Arriving to Customers
3 days ago
Claude Gets Personal Finance Feature With Bank Account Linking
Claude Gets Personal Finance Feature With Bank Account Linking
3 days ago
Apple Arcade Adds Crossy Road Rush and NBA 2K27
Apple Arcade Adds Crossy Road Rush and NBA 2K27
3 days ago
Apple's New HomeView Smart Home Hub: Here's How Much RAM It Has
Apple's New HomeView Smart Home Hub: Here's How Much RAM It Has
3 days ago
iPad Mini vs. iPad Air Buyer's Guide: Now Just $50 Apart
iPad Mini vs. iPad Air Buyer's Guide: Now Just $50 Apart
3 days ago
First iOS 27.3 and macOS Golden Gate 27.3 Public Betas Now Available
First iOS 27.3 and macOS Golden Gate 27.3 Public Betas Now Available
4 days ago
Apple Announces a New Mac Sales Record
Apple Announces a New Mac Sales Record
4 days ago
Paid $200 for Logic Pro? Apple Says You Won't Get This New Feature
Paid $200 for Logic Pro? Apple Says You Won't Get This New Feature
4 days ago