Why can't I get get my Surface Book to extend over 3 monitors?

[Windows Central Question]

Why cant I get get my surface book to extend over 3 monitors

I have 2 display port monitors that plug into a StarTech hub which intern connects to my mini display port on the surface. When I look in the display properties I see 3 monitors listed but can't extend over all 3. I can only ever get the surface to extend over monitor 2 or 3 not both? Does anyone know any issues around display ports?

I am willing to invest in a docking station if needs be but am loathed to spend ?200 if there may be an underlying issue.

Thanks for any pointers.

 

[zerospace-net]

You may need an additional adapter to make a 3 monitor setup work (the GPU likely needs some additional help to drive that 3rd screen). I read a post awhile back that detailed how someone managed to do this, but they used a USB3.0 display adapter in addition to the official dock.

You should also know that there are some pretty obnoxious issues currently with the Surface Book and multi-monitor setups (specifically with waking the device from a sleep state and the monitors not resuming). These issues are widely discussed on Microsoft's support forums.