Hi Res Screen help

[CS DBA]

Hi All;

I've installed Fedora 20 on a Dell XPS 15 with a 3200x1800 screen
It works well but I need a magnifying glass to see the text. I tried 
going into
system settings for KDE and setting the default dpi which sort of works 
for appps
but I still have a teeny tiny start menu and taskbar (and login screen)

If I set the screen resolution to something less than the 3200x1800 I 
get black lines on the sides...


The laptop has an Nvidia graphics card,

any thoughts on how to fix this?


Thanks in advance