Besides the obvious difference between a USB 2.0 vs USB 3.0 port, are there functional/tangible differences across various USB ports on a motherboard?

I'm wondering if some USB ports have functional differences over others, such as higher priority or higher bandwidth.

In Device Manager (Windows 7 x64), each of the 8 USB host controllers have differences in their bandwidth tables, particularly in the "System reserved" parameter (e.g., 20% vs 10%).

Does this mean that some USB ports will be capped vs others? I'm not sure if 1 USB host controller = 1 USB port (the eight seem to line up with the eight USB ports on the back of my motherboard).

I've read that USB shares its resources across the protocol, so I'm wondering if some ports would be better served with particular devices, like an external drive, and putting less data intensive devices on lower bandwidth ports.

  • 2
    It depends on the motherboard. Some have more than one USB controller. Mar 18, 2013 at 3:29
  • As @DavidSchwartz said, it depends on the design. Some motherboards include independent USB controllers, some have a single controller, and some have a small number of built-in ports and expand them with hubs. Each option will affect performance differently, but in general, the ports with a higher throughput (e.g. USB3 > USB2) and less devices attached to their controller will perform better. Finally, one might be able to mitigate any slow-downs by increasing the USB polling rate in your operating system. Mar 18, 2013 at 18:20

2 Answers 2


The only real difference between ports is if they are v3 or not, or if they are powered for use when the machine is off- typically indicated by a yellow port. Other that that ports are identical. What makes them different is the hub they are connected to and, more importantly, the USB controller chipset they are connected to. The controller and hub are what determines their speed, bandwidth, etc.

  • I have noticed that some of my USB ports note "Hub is operating at Full-Speed" and others note "Hub operating at High-Speed". Does this make a difference? there are USB 2 hubs
    – Carl B
    Mar 18, 2013 at 4:38
  • Yes, there is a big difference. en.wikipedia.org/wiki/Universal_Serial_Bus#Version_history
    – Keltari
    Mar 18, 2013 at 12:06
  • I have seen on some PCs that certain sets of ports (for instance, the front ports only) allow "power on from device activity" and others do not. For example, an IR usb device that is programmed to wake a computer from sleep would work on the front ports on a particular model but not the back ports. Of course, this is extremely rare, varied and would only be noticed in very specific applications.
    – user201262
    Mar 18, 2013 at 15:22
  • 1
    @moses - That could also be a setting that can be changed so the rear ports will "wake" the computer as well.
    – Carl B
    Mar 19, 2013 at 1:58

The USB ports that actually touch the motherboard will be faster than the ones on the front some of the times. Its not because of the port but the wiring and circuit board used by the vendor making the front USB board. In reality I have only experienced this like 3 times in past 8 years of repairing machines.

Bandwidth used is the current amount of the total bandwidth being used at that moment. If you start transfer data from a USB drive that port will go up and the others will go down unless something is plugged into them. They will alternate the bandwidth based on which device asked for bandwidth first.

Perform a data transfer test yourself. Use teracopy to get a speed of the transfer and try the different ports. I don't think you will see a difference and they will all be the same speed.

I have seen a motherboard with two different chips for the USB but it was referenced to in the basic manual that came with that motherboard. And they were different in color like red for MSI or something like that.

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