Hello Pete687, welcome to Intel Communities and thanks a lot for posting your inquire.
It is important for you to know that once you install an external PCI express video card, Quick Sync will be automatically disabled.
I would recommend removing the video card from the system and test it using the onboard video just to find out if you are getting the same behavior.
You can also contact the system manufacture for additional troubleshooting, drivers or firmware update.
Pete687, please make sure you installed the latest graphics driver version available which is 3621
- Intel® Iris™ and HD Graphics Driver for Windows* 7/8/8.1 64-bit Intel® Download Center
- Intel® Iris™ and HD Graphics Driver for Windows* 7/8/8.1 32-bit Intel® Download Center
There is a Beta version that you may want to try, but I cannot assure you it will solve the problem you are having. Intel® Download Center
Please let me know how it goes.