What Lurks Within The Latest Big Sur Beta? References To Two Unreleased IMac Models

Researchers have uncovered references to two unreleased iMac models in the latest beta version of macOS 11.3 Big Sur, raising the prospect of an imminent refresh.

Released earlier this week, the latest macOS Big Sur beta listed two new model identifiers: iMac21,1 and iMac21,2*.

These are believed to be same machines revealed by Bloomberg earlier this year, which had the internal codenames J456 and J457.

Per the report, Apple intends to replace the existing 21.5-inch and 27-inch iMac models with two new designs. While it remains unknown how much screen real estate they'll carry, Apple analyst Ming-Chi Kuo has claimed the entry-level model will pack a larger 24-inch display.

Other leaked information have pointed to a wider redesign, with Apple expected to provide a range of colour options reminiscent of the original iMac G3 as well as a flatter and slimmer chassis given the lower thermal output of Apple's homegrown ARM chippery.

Previous iMac versions contained hefty cooling fans designed to dissipate the massive amounts of heat generated by the CPU and GPU, as well as plenty of dead space to allow for airflow.

By contrast, the latest M1 MacBook Air chugs along contentedly with a solid-state passive cooling system, with barely any difference between it and the fan-cooled M1 MacBook Pro in terms of performance.

Further space savings could be found by removing the user-serviceable RAM and storage. Considering Apple's adoption of a unified memory architecture, where the RAM sits on the same package as the CPU and GPU to allow for faster access, as well as soldered on-board memory, this seems likely. Right-to-repair advocates are less likely to be impressed, however.

In recent weeks, Apple has pared back its legacy Intel iMac portfolio, discontinuing the iMac Pro and certain configurations of the base 21.5-inch model. Additionally, one developer has claimed to have received an automated Xcode crash report from an unknown ARM-powered iMac. This has led some to believe that the launch of the debut Apple Silicon iMacs is imminent. Although it's not exactly certain when that would happen.

Apple was expected to hold its traditional spring launch event in mid-March, bringing with it a refreshed iPad Pro lineup, new iMacs, and the long-expected (and legally contentious) AirTags device-tracking gadgets. With the month almost over, the grapevine is now looking towards April for Cupertino's next event.

In the meantime, if you can't wait, you can always play Dr Franken-tosh and craft your own using an M1 Mac Mini and a knackered older intel iMac. Or, if you're exceptionally mad, an iMac G5 that would be almost old enough to drink, were it a person. ®

*No, that's not a typo. Apple has a tendency to "think different" when it comes to its model identifiers, using a comma where other vendors might use a period.