Hello,
Thank you for your interest!
DisplayLink chips or drivers are not GPUs. Computation of pixels handed over to DisplayLink are done by the GPU. Windows sends calculation to the GPU.
Impact of performance of what and doing what would be my return question. Everything has a cost! Plugging a second monitor, hard drive or running any piece of software will add load on different elements: buses, GPU, CPU... Most people ignore GPU load because Windows doesn't provide an obvious bar graph for it, except maybe with a temperature gauge.
As laptops are getting skinny, a proprietary connector dock may use a serial bus like USB and therefore will not necessarily offer a better throughput. A proprietary connector dock is pretty much throw away when you change machine. A real standard USB dock will bring you universality. By real USB, I mean USB connector hosting USB traffic, not another format over a USB-C connector for instance...
My work machine is a Surface Pro 3. The other day I wished to do something on my Android phone... I unplugged my tablet and
plugged in my USB-C Android phone!
DisplayLink driver will use CPU as we need to ship these pixels through the USB, fast, and in a clever manner to achieve the low latency keeping the pixel-perfect we are known for.
But the algorithm we have use what is available and, like a clown, juggles with CPU bandwidth, USB throughput available, what we must send... transparently.
We have demonstrated
quad 4Kp60Hz over a single USB3 link. Nobody else has yet... especially when it works on USB Type A too. Traders can have in excess of 15 displays!
However, the primary use case of our technology is universality for productivity, not gaming. We test for productivity, video playback so we know it works reliably. We do not test games and they use multiple ways to address graphics, some bypassing the standard Windows Desktop Manager and this was causing issue on older versions of Windows, so we don't advise it.
Being obviously biaised (!) without having a discount, I would still buy a DisplayLink dock. I have two proprietary connector docks at home I can't use anymore, that's enough. So I would choose option 2.
If you have a really high end graphics card in the laptop and sometimes launch seriously demanding gaming which leaves you no CPU bandwidth available, then you can always temporarily move the HDMI connector... But I don't see the USB latency or throughput being any limitation to you.
Oh, and any product using DisplayLink technology with a Type A connector can already be used over the newer Type C with a passive plug adapter as we use standard USB.
What resolution do you expect for your external monitors?
Kind regards,
Alban