Greetings,
There are just too many variables to consider based on your initial post.
A few questions.
-Does the crash occur when you use a specific application, or just happen randomly?
-What is the brand, model and speed of your memory?
-What resolution are your running on the 2x Sony 55" displays?
-What happens if you only run 1 display?
-Have you tried different HDMI cables?
-Are you using any type of cable adapters?
-BIOS update? For what.. the motherboard or the GPU?
-Do any errors appear in the System Event Viewer (relating to the crashing)?
We may have more questions based on your responses.