This is part #1 in a series in detailing some of the interesting pain points of adding a high-dpi monitor to the mix of a few regular screens.
Part #1 Different Scale Monitors
Part #2 Applications and "DPI Aware"
Part #3 Playing Nicely With The Rest Of The World
To set the scene, my setup is as follows:
- 1x 28" 3840x2160
- 2x 24" 1920x1200
I'd like to scale the 28" to 150% to provide a nice balance between usable resolution (effectively 2880x1620). The 24" displays I would like to remain as is, without any scaling applied.
Windows 8.1 supports two different modes for dealing with high DPI monitors:
You can either set the scaling level for all displays
This obviously works well when all monitors are the same DPI, however breaks down with mixed sizes/resolutions.
Or you can opt out of that model and determine scaling independently.
In this mode, Windows will determine the best DPI scaling value for each display and use separate DPI scaling values for each display when needed.
In practice, this falls entirely apart. Having the 28" High-DPI screen scaled at 150% also scales the 24" monitors and there is no way to disable this. This appears to be based on the vertical lines in screen resolution (and does not take into account the physical size of the screen).
| Vertical lines in Screen Resolution | Supported DPI scale factors |
|---|---|
| < 900 | 100% |
| >= 900 and < 1080 | 100%, 125% |
| >= 1080 and < 1440 | 100%, 125%, 150% |
| >= 1440 | 100%, 125%, 150%, 200% |
Sticking with how this impacts Windows for now, this is how this plays out on the 24" screens.
Issue #1 - Enormous taskbar
(note as well Chromes lo-fi icon vs. HipChats)
Issue #2 - DPI aware apps are still scaled.
The icons in explorer are the "correct size", however everything has still been scaled and is heavily anti-aliased.
All applications that are DPI aware seem to apply this same scaling. They look absolutely fantastic on the 28" and look like total garbage on the 24"
Issue #3 - Icons on the desktop
Icons on the 24" screens desktop are 2x the size of the 28" screen. So whatever scaling is being applied throughout Windows Explorer is not being applied on the desktop. Perhaps it isn't DPI aware?
Issue #4 - Resuming from Sleep
Upon resuming from sleep, all open apps that are not "Metro" are moved to the primary 28" screen.
Stay tuned, more to come...