Does USB 3/3.1 docking station use internal GPU capabilities?

Question

I'm looking for a new laptop, used both for professional and personal use (target is core i7/16Go/any non Intel GPU).

I want to plug two external monitors (24" Full HD), while keeping GPU performance intact (for some games or some high resource consuming apps).

My current laptop (Dell latitude) has a very convenient proprietary docking station with everything required to make it works as exepcted.

However, I can see that recent laptops are either

• professional usage targeted (Lenovo T560, Dell XPS 15), with compatible docking station, but very expensive
• multimedia/gaming usage (Lenovo Y700, ...) with no specific docking station. Quite less expensive for same performances than the former.

In the second case, I'd buy a USB 3.1 docking station, to plug my monitors and common devices (keyboard, mouse, ...).

In this setup, is the internal GPU still the one that do the job (and then keep the performance whichever screen is used)? Or does the docking station has an inner GPU (which should probably be low performance) ?

Answer 1

I'm assuming you are referring to using a USB type C dock. If that is the case then the port will only act as an out, which means all the processing will ideally be done by your internal GPU. My only concern here is, looking at the current list of products available, I was able to find only a few docks with multiple display slots using USB 3.0. And at USB 3.0 you are restricted to the resolution you would be able to pull for two monitors. With Thunderbolt via USB 3.1 Type C you have a much higher bandwidth to work with. Maybe have a look at laptops with thunderbolt capabilities.

Note: I wasn't able to find anything with USB 3.1 and no thunderbolt.

Answer 2

I don't have any definitive answers, but from jphughan's post here: https://www.dell.com/community/Laptops-General/Utilize-dedicated-XPS-15-GPU-when-using-docking-station/td-p/5165572

Basically, in almost all modern laptops, the dGPU is not physically wired to any display outputs; instead, it acts as a render-only device that passes completed frames to the Intel GPU, which IS wired to the display outputs.

So in the above scenario you're still limited to what the Intel GPU can output as far as final render frame (resolution, color space etc) even though you're leverage the dGPUs power to render complex scenes. Apparently there are some laptops out there that tie the dGPUs directly to the thunderbolt port.