Apple iMac Pro to come with a 20-core M1 Max Duo SoC that combines two M1 Max dies
Last month, Mark Gurman reminded people of Apple's plans to release even more powerful in-house SoCs for the Mac Pro. As he reported earlier this year, Apple is thought to have developed SoCs with up to 40 CPU cores and 128 GPU cores, 4x the volume of CPU and GPU cores that the M1 Max offers.
Reputedly, Apple has a lesser SoC with 20 CPU cores in development too, which is tipped by AAPL Tree and Max Tech to appear in a 27-inch iMac Pro. Supposedly, Apple will bolt two M1 Max dies onto one SoC, allowing it to offer 128 GB RAM support, currently a feature of the Intel-based 27-inch iMac.
The so-called M1 Max Duo would also have double the GPU performance (TFLOPs) of the M1X and its 32-core GPU. As Max Tech discusses below, the M1 Max is more powerful than the RX 5700 XT in the 27-inch iMac, but not by enough of a margin that could be considered a generational leap. Theoretically, offering double the GPU performance of the M1 Max would achieve this.
Additionally, the M1 Max cannot compete with the CPU performance offered by the Core i7-10700K or the Core i9-10910. Hence, equipping a 27-inch iMac with the M1 Max would be a downgrade in terms of CPU and GPU performance. Offering a second M1 Max on the same chip could help Apple bridge that CPU gap, too.
Incidentally, Hector Martin, who is porting Linux for Apple Silicon Macs, has discovered 'plenty of multi-die references' in macOS. Additionally, he states that Apple has designed the M1 Pro and M1 Max's Interrupt request (IRQ) controllers with second halves for a second die. Currently, this second half is unused.
Apple is expected to reveal a 27-inch iMac in Q1 2022 with a mini LED display. The PC is thought to offer a 120 Hz 'ProMotion refresh rate, as well.