Dell monitor resolution issues

Isn't the native resolution of that monitor 1920 x 1200?

Also how is it connected to your Mac?

 

I've got the same monitor connected to my rmbp using a mini display port to display port cable. No problem with resolution. What's the problem you're having. The usb hub is a load of crap though.

 

Make sure you're not using screen mirroring; you'll be limited to the maximum resolution of your MacBook's display.

 

I'm sure the display is only 1920x1080

 

Per Dell's specification page on this display:
Optimal resolution:
1920 x 1080 at 60Hz

Important question that you haven't yet answered:
What kind of cable are you using to connect the monitor to the MacBook?

Also, check the display's input settings.

Although I've never experienced the problem, I've seen a number of postings here at MacRumors from folks who had Dell displays that wouldn't connect right because the Mac was trying to sync to them "as tv's", rather than as a "computer display".

There is a workaround for that...

 

Some links to check out regarding how you might have to "force" OS X to "recognize" the Dell display in "RGB" mode (instead of "as a tv"...):

http://www.experts-exchange.com/OS/Apple_Operating_Systems/OS_X/Q_28410313.html

http://www.ireckon.net/2013/03/forc...ix-the-picture-quality-of-an-external-monitor

http://forums.macrumors.com/showthread.php?t=1713591

http://embdev.net/topic/284710

 

I had the same issue. I was using a thunderbolt adapter to connect to the VGA from Dell monitor and the VGA was loose. Once I tightened it, resolution became fine.