try like this. hope it works
drawable-sw720dp-xxhdpi and values-sw720dp-xxhdpi
drawable-sw720dp-xxxhdpi and values-sw720dp-xxxhdpi
link might destroy so pasted ans
reference Android xxx-hdpi real devices
xxxhdpi was only introduced because of the way that launcher icons are scaled on the nexus 5's launcher Because the nexus 5's default launcher uses bigger icons, xxxhdpi was introduced so that icons would still look good on the nexus 5's launcher.
also check these links
Different resolution support android
Application Skeleton to support multiple screen
Is there a list of screen resolutions for all Android based phones and tablets?