The screen on the iMac with 5K Retina Display screen will have four actual pixels – two vertical and two horizontal – for each effective pixel. That simply means a monitor where your effective number of pixels displayed is less than the actual number of pixels displayed. People buying a 4K monitor today see the same issue, but there is now an easy way to get that running in Retina mode.Īpple’s solution to this issue was to introduce what they call “Retina displays” on Macs. If your monitor’s native resolution was too high, you were plagued with either living with small text or running the screen at a lower resolution. In the old days when you purchased a monitor you had to decide between higher resolution and larger text.