Using USB splitter with USB-C Macbook pro 2016 I want to connect 3 USB 3.0 devices to my MacBook Pro 2016. I'd like to do it through a single USB-C port using this a USB-C to 3 USB 3.0 hub like this one. Question!

When I connect a single 3.0 device through the hub the maximum theoretical speed is 5Gb/s, right?
If I connect two 3.0 devices and read from them at the same time. Will each of them still transfer data with the speed of up to 5Gb/s or is it going to slow down? In other words, when the device says it provides 4 3.0 ports, does it use 3.0 protocol to talk to the laptop, and thus has to 'share' the 5Gb/s bandwidth among all the devices? OR does it take advantage of the usb-c port. In the case of the latter, does it then have 10 Gb/s to distribute (usb 3.1 protocol) or 40(thunderbolt 3).
You won't get faster than USB 3.0 speed on the link to the Mac or any of the hub links. (You'd need a thunderbolt 3 hub for that.)


USB 3.0 theoretical speed is 5 Gbit/s
USB 3.1 theoretical speed is 10 Gbit/s


Theoretically - when you have a hub, there is overhead and losses and those depend on the quality of the chipset in the hub.

In practice - what is going to be providing or consuming data at even 3 Gb/s - not much. Get the hub you like for the support and price and warranty and when you have an actual performance issue - you can profile it and get a second hub or offload the one device to another port.