Thanks for reaching out to us, I’d be more than happy to answer your question regarding the performance you are getting.
As a note, we’ll try to see if there is anything we can do to improve the performance, but it is also possible that you are simply hitting the performance capabilities of the system. Essentially, the two connected monitors are virtual devices, meaning that the heavy lifting/processing is done by the Surface Pro 2. In general, we advise against using USB connected monitors for system taxing processes like video playback, the best use case for performance is more static material like website content.
First, if you remove one of the connected monitors and try running the same video content, is the performance better or worse?
Second, can you try disabling all other programs running concurrently on the system other than the browser running the video. Does the performance change at all?
Lastly, you may want to try updating to the latest DisplayLink drivers:
Disconnect the adapter from the computer.
Run the DisplayLink Cleaner tool to completely uninstall existing DisplayLink Software:
Download driver v7.7 M2 from the below link and follow the installation prompts.
Reboot the computer.
Replug the adapter to the computer. Allow several minutes for the driver to enumerate and for the firmware upgrade to complete.
Does this help at all?