USB 3.0 throughput using multiple ports

Question about the USB 3.0 ports on the current generation Mac Mini: The theoretical max throughput is 5.0 Gbit/s for USB 3.0. If I have more than one USB 3.0 device connected, both trying to xfer data from the device to the Mac Mini, am I limited to the 5.0Gbit/s shared across all devices, or is there hardware behind each of the ports that would keep the throughput 5.0Gbit/s for each.

(sub-question, does the thunderbolt xfer in any way impact usb xfer rate if working at the same time.)

Theoretical max is for each USB port. It isn't shared between ports, and Thunderbolt wouldn't interfere with USB transfer speeds on the hardware level, but the bottleneck is going to the CPU and Memory performance..

So if you have multiple applications trying to transfer lots of stuff to different devices over USB and Thunderbolt..they'll all start limiting each other..