Almost a year ago, Apple put a Retina display inside its 27-inch desktop. A report from 9to5Macsays we could see a high-res panel on the smaller 21.5-inch model soon as well. The word comes from Mark Gurman, who has a solid track record for news like this, of the new iMac initially tipped by clues inside the upcoming OS X El Capitan. Despite the larger all-in-one getting a 5K Retina panel last fall, the report claims that the 21.5-inch version will come equipped with a 4K display and resolution of 4,096 x 2,304 (up from the current 1,920 x 1,080). While Apple has an iPhone-focused event scheduled for next week, Gurman says the new iMac won't be announced until next month. If you're not too thrilled about paying a premium for a higher-resolution display, chances are the current model will remain available. Even after the 27-inch Retina model arrived, the 1440p option stuck around.