Jeromy Anglim's Blog: Psychology and Statistics


Tuesday, December 15, 2009

Problems with High Resolution Laptops and External Monitors

In this post I outline why buying a high resolution laptop is a bad idea if you ever plan to use an external monitor and run an extended desktop.

I really like running a dual monitor configuration. My laptop provides one screen (15.4 inch screen running at native resolution 1280 x 800) and a 24 inch external monitor (1920 x 1200) provides the second. I use Ultramon to manage the configuration and move windows between the two monitors.

I was recently exposed to a 15 inch laptop with a 1920 x 1200 native resolution. My 24 inch external monitor also runs natively at 1920 x 1200. By default the laptop ran at 120 DPI (large size). At 120 DPI fonts were readable on the laptop, but the fonts on the external monitor were too large and blurry. If I switched the DPI to 96 DPI (normal size), the external monitor looked great but the fonts on the laptop were tiny and strained the eyes. Lowering the laptop resolution to a non-native resolution also resulted in poor picture quality.

I did a few Google searches and found out on Superuser that:
  • This is a known problem with high resolution laptops. 
  • Windows (XP, Vista, and 7) does NOT allow for setting the DPI on a per screen basis
My advice for users: If you use a laptop with an external monitor, you need to think about how it will look with the external monitor. Native DPI settings should be paired. Laptops with high resolutions relative to the screen space are a bad idea until they make external monitors with similarly high ratios.


My advice for companies that sell high resolution laptops: Notify the customer prior to purchase of the limitations outlined above regarding running the laptop in a dual monitor configuration.

Request to Windows: Enable DPI changes without the need to log-off.