Multiple monitors over one USB 3.0 connection?

[Shmael1053]

I’ve been helping my stepdad set up a laptop dock in his home office for WFH. His laptop is slightly older - a Lenovo Flex 5-1470 - but it does have one USB-C 3.0 port. He bought two 1080p monitors that use HDMI, and a cheap USB-C dock from Best Buy. The dock would only allow one monitor to display at once, and when he called the support number for the dock, they told him that the dock he had (which supported up to USB 3.1 gen 1) supported simultaneous HDMI and DisplayPort output but not simultaneous HDMI, and that he just needed to buy one of their more expensive docks. I’m understandably suspicious of that claim.
I’ve been looking online to see if USB 3.0 has support for multiple displays over a single connection, and haven’t been able to find any information other than “you can convert USB-C to HDMI”
Is it possible to connect multiple displays to a single USB 3.0 connector? Keep in mind this is 3.0, not either generation of 3.1, and both displays are 1080p.

[Glenwing]

The HDMI protocol doesn't support multiple displays on a single port. You would need to use DisplayPort over USB-C to have multiple displays from one port.

 

USB generation is irrelevant as the video signal is passed through from the video card using the DisplayPort protocol, not packaged in a USB signal.

[Alex Atkin UK]

Video over USB is never a great idea as its entirely software driven, it uses a TON of CPU power so I'd be shocked if it was worth doing over two monitors to begin with, even one is questionable.

 

I'd use the built-in HDMI port for anything intensive such video and use the dock only for relatively static use.  Its unlikely to be a particularly pleasant experience otherwise.

[Glenwing]

51 minutes ago, Alex Atkin UK said:

Video over USB is never a great idea as its entirely software driven, it uses a TON of CPU power so I'd be shocked if it was worth doing over two monitors to begin with, even one is questionable.

 

I'd use the built-in HDMI port for anything intensive such video and use the dock only for relatively static use.  Its unlikely to be a particularly pleasant experience otherwise.

USB-C supports video passthrough from the graphics card.

[Alex Atkin UK]

17 hours ago, Glenwing said:

USB-C supports video passthrough from the graphics card.

Only on a very limited selection of high-end laptops, not the Lenovo Flex 5-1470.