I am running PhpStorm 2017.2 on Windows 10 and experiencing a scaling problem where everything in my IDE (not just editor windows) looks bigger.
I am running it on laptop Asus Zenbook 13" with 1920x1080, by default this screens scaled using 150% (recommended) settings (Windows Display Settings). The other 2 screens are 24" with also 1920x1080 resolution and the scaling setting is set to 100% (recommended).
The PhpStorm looks OK on the laptop screen, but it looks like it's also scaled to 150% on the other screens, even though it shouldn't. I've tested whether actually "scale" settings on the other screens affect the PhpStorm appearance and for some reason changing the "scale" doesn't affect PhpStorm. Different applications (e.g. Google Chrome) or task bar are resized correctly.
Here is a screenshot, how big is the PhpStorm on the 24" screen (compare it to the task bar icons size).
Any ideas? I am back to Windows (after 7 years), had to switch from Ubuntu due to driver issues on this particular hardware.
EDIT:
After adding the -Dsun.java2d.uiScale.enabled=false as per @lena answer the size is now correct, but fonts are messed up. They're unclear on the external screens, but good on laptop screen.
EDIT2:
After doing this:
Shortcut of PhpStorm > Right click >Properties > Compatibility tab > Select "Override high DPI" - choose: "System"
PhpStorm looks sharp on the External screens, but doesn't on the primary laptop screen.
