Not all M1 iMacs are built the same: Potential buyers of the 2021 Apple iMac 24 should be aware of the cooling system differences that could affect performance
Only US$200 separates the base M1 iMac with the mid-tier M1 iMac at the moment, with the former costing US$1,299 and the latter US$1,499 (with 256 GB SSD). There is also a high-end iMac 24 with a 512 GB SSD for US$1,699, but this has the same build as the mid-tier model. The well-publicized differences between the base model and mid-tier device include the presence of two USB 3 ports, an extra three colors to choose from, and preconfigured Touch ID sensor and Gigabit Ethernet for the more-expensive iMac. On top of that, buyers of the US$1,499 device get an M1 processor with an 8-core GPU while the cheaper model sports a 7-core GPU.
If that’s not enough to sway a fan to pay an extra US$200 for the mid-tier model, somewhat undisclosed details about the M1 iMac’s cooling system might be enough to push some over. Many people will be making a purchase decision for the 2021 24-inch Apple iMac based on the fact that it features the ARM-based M1 chip, and while Apple has been clear about the GPU core count differences, less has been mentioned about the cooling fan count: The base iMac 24 has one cooling fan whereas the mid-tier model comes with two cooling fans. Obviously, this indicates that the M1 in the more-expensive iMac could manage load for longer periods of time thanks to the superior cooling solution.
The differences don't just end with cooling fan count though; apparently, the mid-tier 2021 iMac also has a heat pipe to help with the thermal emissions while the base model has to make do with its one fan and a heat sink. These cooling system differences and Apple's “oversight” in not mentioning them on the official iMac 24 product pages (no details at the time of writing) have been pointed out by TechTubers like Luke Miani, Brian Tong, and Max Tech.
An image recently shared by an alleged Apple engineer showed the new iMac with two cooling fans and an iFixit iMac teardown also revealed a device with two fans. However, an X-ray image provided to iFixit by Creative Electron clearly shows an iMac 24 with a single fan (see below). With this in mind, and including all the publicized differences, M1 iMac buyers would be wise to pay up the extra US$200 for the mid-tier model, especially if the better cooling system gives the M1 more thermal headroom for its much-vaunted processing performance.
So apparently the base model 24” iMac has only one cooling fan compared to 2 on the higher tier models. I’ve no idea why ????♂️— Luke Miani (@LukeMiani) May 23, 2021