Can't mirror display properly
 

Hello.
I have a Monoprice USB to HDMI adapter, using the DisplayLink 2.0 software on my Macbook Air. While running my external display in Arrangment mode with the Display preferences works ok, Mirror mode doesn't work well. It does mirror, but the image on the external display is constrained to the middle of the display, and does not occupy the full 1920x1080 resolution. (I want to run the external display off USB (in mirror mode) so I can hook up a firewire device to the Thunderbolt/Mini-DV port).

Also, this adapter is USB 2.0 and video and screen movements are very choppy. I'm not sure if a USB 3.0 adapter would be better.

All in all, very disappointing and a lot of time wasted tinkering around and on chat with Monoprice.

?

Mirror is mirror. In short, it's constrained to the dimensions of the host's display. What behavior are you expecting (some type of stretch mode?)

You'd be better off extending the desktop to the external display. You can relocate the system menu and Dock icons to the external display, if you want it to be the 'primary' for times that you're docked.

As far as performance -- yes, USB 3.0 makes all the difference (5Gb/s vs 480Mb/s). What generation of MBA do you have? I had performance actually take a dive on USB 3.0 (on a Windows box) when matched with a system with an older CPU (AMD K2), depite a PCI Express USB 3.0 card...

I was expecting the same mirror behavior that happens when I plug in the same external display to the Thunderbolt port: Full screen.

The problem with extending (or arrangement mode)this is that the mouse cursor and Finder/Application windows can be moved off screen (onto the laptop screen), even with the Macbook lid closed. If I wanted to use Macbook and external display, this would be fine.

It's a 2012, so it has USB 3.0.

What you want is to make the external display primary then (while deactivating the notebook's display), which isn't DL's definition of mirroring. My MBA is not plugged into my docking station right now -- I know that option exists for the Windows DL drivers. Perhaps a DL employee can chime in here.

Personally, I end up leaving my MBA's screen on and active, off to the side. It's a great option for flinging a background window (like my Slingplayer or webcam) off to the side, allowing me to use my primary display without any topmost windows obscuring anything.

I have a 2012 i5 MBA here with a Plugable UD-3000 dock. I would definitely opt for a USB 3.0 solution -- overall performance and responsiveness to my 1920x1080 display is outstanding. Since you're not using the MBA's display, are you using an external keyboard and mouse as well? If so, I'd definitely recommend a full fledged solution like the Plugable. You'll also gain a gigabit Ethernet wired connection -- although that's a little touchy with the current 2.0 drivers (problems obtaining in IP when coming out of sleep periodically).

I think Apple call this Clamshell mode:

http://support.apple.com/kb/HT3131

Unfortunately Mac OS X does not recognise DisplayLink displays as external displays, so you cannot use Clamshell mode (eg just DisplayLink displays) on your Mac and turn off the laptop screen.

Wim