How to check if a USB hub supports USB 3.0?
Open System Information app before you plug in your hub. 
Navigate to "USB" in the list and click. 
Note which information isn’t about the device you’re about to test.
Then plug in the hub and refresh the window contents. 


Here is an example of mine. You can see it is identified as USB 3.0 capable, speed up to 5Gb/sec: