Re: DELL U2713HM not USB 3.0
The USB ports on U2713HM are USB 3.0. You may refer to User's Guide Here.
Please share the system model you are using with monitor as the system should also be USB 3.0 capable.
You may refer to Setup Diagram Here. The monitor Upstream cable is in Step 4 and should be connected to a USB 3.0 port on computer.
Do reply with the information. I would be glad to help you.