I use a 27″ 4K monitor at 150% scaling on Windows 10.
For DPI-aware applications (Visual Studio 2019, Office, modern browsers), text looks sharp.
However, DPI-unaware applications are virtualized by Windows and appear blurred because they seem to be rendered at 96 DPI and then bitmap-scaled to the target size.
Why doesn’t Windows use a supersampling approach instead?
Current pipeline:
96 DPI render
→ upscale bitmap to 150%
→ display
Hypothetical pipeline:
96 DPI render
→ upscale to 200%
→ downsample to 150%
→ display
This would be similar to supersampling anti-aliasing and would not require changing the DPI reported to the application.
Would this improve quality for DPI-unaware windows?
Is there a technical, architectural, performance or compatibility reason why Windows does not do this?
