Over the past year we’ve seen growing list of new devices equipped with very high-resolution screens at 1440p or higher at 4K. In most situations, you will need to enable display scaling level so that the text is readable at a comfortable reading distance. Windows 8.1 is smart enough knowing what level it should be based on the resolution of the screen. And it works really well when it only has one screen to work with.
However, you could only enable one scaling level for all monitors, it’s super annoying when you have a high-resolution screen paired with a set of standard monitors that only have normal resolution at 1080p, such as pairing my Surface Pro 3 with a set of 2 1080p external monitors. If the main display is a 1080p monitor, the text size would be so small on my Surface that I can hardly read them. And if the main display is the Surface Pro, the text would be too big on the 1080p external monitors. There is just no mid-ground that suits well for both side of the world.
Not anymore on Windows 10.
With Windows 10, you can set display scaling levels for each individual monitors attached on your computer. For those pairing a 4K monitor with a 1080p monitor of the same size, this means you can set a scaling level of 200% for the 4K monitor and 100% for the 1080p monitor, and items will appear the same size on both displays.
It also works perfectly for my case mentioned above as well. I can now keep the same scaling level for my Surface while adjusting the scaling level for the external displays so I can get the proper text size on all monitors.
Finally, I can read well regardless of which displays I am reading on.
To do so, go to Settings app → System → Display, select one display, adjust the scaling level, Apply the setting, then do the same to the other displays. Note that you need to Apply the setting on one display before changing to the other display.