[JamesH]

Originally Posted by kingsapo

Hello. I recently bought a StarTech USB 3.0 Dual Head Graphics Adapter (with the DL 3900 chipset) for my mac. This adapter uses USB 3.0, and runs great under the standard configuration. However, I had intended to use it with a monitor that supports rotating to a portrait orientation. While the Mac's system preferences support rotating the video, it does so at a huge performance cost. Under landscape mode, everything is nice and smooth, and there is no noticeable lag at all. Under portrait, however, there is a huge amount of lag, from simple things like moving windows around to blocky and laggy screensavers.

I'm pretty sure this is a driver issue, since switching my other displays (which are using the built-in graphics) to portrait doesn't result in any of these issues.

I am running OS X 10.8.4 with the 2.0 version of the DisplayLink drivers. I have also included my system report, in case that is needed. Thank you for any help you can offer!

Hi,

Please attach the output of the support tool.
http://www.displaylink.com/support/ticket.php?id=269

Thanks,
James