Update: Hours after this story was published, Apple updated the tech specs for the new iMac to indicate that configurations with the 10-core M4 chip support one external display with up to 8K resolution at 60Hz, not 120Hz. It appears that the original 8K at 120Hz specification in Apple's tech specs was an error. Apple still mentions 8K at 120Hz on its international websites, but those will likely be corrected soon as well.
Original story follows.
When configured with a 10-core M4 chip, the new iMac announced today supports up to an 8K external display at 120Hz, or up to two 6K displays at 60Hz each. The impressive feat was noted by Vadim Yuryev, co-host of the YouTube channel Max Tech.
This means the latest iMac is the first-ever Mac to support an 8K display at 120Hz, beating out higher-end models like the MacBook Pro, Mac Studio, and Mac Pro. Apple is expected to announce new MacBook Pro models with M4 Pro and M4 Max chips as early as tomorrow, however, so support for an 8K display at 120Hz could be expanded soon.
Apple doesn't even offer an 8K display with a 120Hz refresh rate — at least not yet. Apple's higher-end Pro Display XDR monitor has a 6K resolution at 60Hz, while its lower-end Studio Display monitor has a 5K resolution at 60Hz.
Does the iMac's external display support hint at future 120Hz versions of the Pro Display XDR or Studio Display? There are no concrete rumors yet.
The previous iMac with the M3 chip supports one external display at up to 6K/60Hz, and this remains true for the latest base model with the 8-core M4 chip.
For more details about the new iMac, read our earlier coverage of Apple's announcement.
In the U.S., pricing for the iMac with a 10-core M4 chip starts at $1,499.