I read that a switch is for people who require more lan ports right? I have a asus router with 4 ports so no issue for me ,now I'm deciding between running 2 cables to room or 1 cable + switch? Performance is top priority.
Example of layout:
Main Router --> data point --> room data point --> Switch --> Router-2 | PC | PC | devices
Firstly you need to have the to run 1 ethernet cabling via trunking from the Main Router to room with both ending with data points RJ45.
In the room data point then connect to Switch (required power supply).
Switch is usually smart auto switching device with 5 or more ports and which act as additional ports.
There will be no loss in performance and reliability as the switch purpose is to increase the ports as similar to router lan ports.
Room data point to Switch for all devices such as router, computers, tv box, and other devices, etc.
Note that router can be used as additional Access Point for wireless signal coverage for mobile devices.
Of course you can run 2 ethernet cables within the trunking as an option.
But in the end should you need additional ports for other devices then you still required this Switch.
For your info i am using a switch in my bedroom and connected to router and laptops.
In my case as i am using Starhub Fibre TV which required a separate ethernet cable link between ONT Port-2 and TV STB (Set top box) in my room.
In other word i have 2 ethernet cables or data points for 2 separate purpose.
Starhub Fibre TV STB has to be separate from internet access.
Starhub Fibre Broadband is using ONT Port-1 to main router and end into my room data point connected to the Switch.
So if you want to "play safe" then run 2 ethernet cables for future purpose if needs arise.
Note that Splitter will split into 2 ports and to have the speed of up to 100mbps each port even if you subscribe to 500mbps or 1Gbps plan.
