If you’re running DragonFly-master and you have an Intel video chipset, Francois Tigeot has an update for you. It brings accelerated Intel video up to match the Linux 3.14 version, adds Broadwell chipset support, and should generally improve performance. He lists how to test right in the message.
A running description of activity related to DragonFly BSD.
What about AMD radeon video?
http://www.dragonflydigest.com/index.php?s=radeon
If I know it, I’ve posted it. The most recent post mentions a branch for testing – assuming you have the hardware, can you test and provide feedback to the author?