https://www.cnbc.com/2019/03/19/apple-imac-4k-and-imac-5k-refreshed-with-9th-gen-intel-chips.html

Apple on Tuesday updated its 21.5-inch iMac with Retina display and 27-inch iMac with Retina 5K display with new processors and graphics chips that include a lot more power. The company's entry-level iMac without a Retina display was not updated.

The new 21-inch iMac with 4K display will start at $1,299, but you'll need to pay more for the bump up to the new six-core processor Apple will offer. The 27-inch iMac with Retina 5K will start at $1,799. Both go on sale Tuesday and ship next week.