According to French website Macbidouille, they have discovered within the OS X 10.10 Yosemite there is a file that defines display scaling resolution options for a machine that has since been identified as an iMac. Based on their findings, it seems that the file includes scaling resolution options that will max out at 6400×3600.
However it has been speculated that it will most likely end up being lowered to around 5120×2880 which would be double that of the 27-inch iMac. Alternatively it could also be scaled to 3200×1800 for a Retina iMac. It’s interesting that Apple has included scaling options because it was just the other day that Apple had scaling options in Xcode 6 for iPhones and iPads, hinting that larger iPhones and iPads could be in the works.
Like we said earlier, there have been talks about Apple possibly giving the iMac a Retina treatment, but apparently cramming that many pixels into a display as large as a 27-inch iMac has been a challenge. No word on when Apple will debut these alleged Retina iMacs, but given that there was no iMac-related announcements at WWDC 2014, perhaps there’s a chance we’ll still hear about it later this year.