Currently display port has no EDID read during standby or power saving monitor modes. That means that the OS will automatically drop the resolution to a lower resolution when your monitor is off or goes into a stand by state. Once its woken up the display port receives the EDID information from the display and will then correctly adjust the desktop to the correct resolution. However, sometimes the application windows will remain in a 800x600 size. In the future Displayport input may support stand-by EDID reading, however at this time it is unavailable.