Using USB 3 devices on Mac computers

Learn more about using USB 3 ports and devices on Mac computers.

  1. What is USB 3 ("SuperSpeed USB")?
  2. Does my Mac support USB 3?
  3. What transfer rates does USB 3 offer?
  4. Does USB 3 offer more power than USB 2 ("Hi-Speed USB")?
  5. Why don't I see blue inserts on the USB ports of my Mac?
  6. What USB 3 devices are supported?
  7. Are USB 3 hubs supported?
  8. How do I get the best performance from the USB 3 ports?
  9. What happens if I plug in a USB 2 device into the USB 3 port first?
  10. What happens if I plug my USB 3 device into a USB 2 port?
  11. Is USB 3 supported in Windows 7 and 8 using Boot Camp?
  12. Are there differences between USB 3 cables and other USB cables?
  13. Can I use a USB 2 cable to connect a USB 3 device to my computer?
  14. How can I determine if my device is connected as a USB 3 device?
  15. Why do my USB 3 devices seem to only work at USB 2 speed when I use virtualization software on my Mac?
  16. Why don't some USB 3 devices activate or appear on the USB 3 bus?
  17. Why do I have difficulty with Wi-Fi or Bluetooth devices when USB 3 devices are attached to my computer?

What is USB 3 ("SuperSpeed USB")?

USB 3 (also known as "SuperSpeed USB") is the latest USB standard which offers significant performance improvements over USB 2 ("Hi-Speed USB").

Does my Mac support USB 3?

You can use System Information or System Profiler to see what type of USB ports your Mac has, how fast these ports are, and what's currently connected to them. Learn more about identifying USB ports on your Mac.

What transfer rates does USB 3 offer?

  • USB 3 can transfer data up to 5 Gbps.
  • USB 2 can transfer data up to 480 Mbps.
  • USB 1.1 can transfer data up to 12 Mbps.

Does USB 3 offer more power than USB 2 ("High-Speed USB")?

Yes, USB 3 devices can use up to 900mA of power (compared to 500mA used by USB 2 devices). You'll need to use a USB 3 cable to use the 900mA of power available. USB 2 cables don't support 900mA.

Why don't I see blue inserts on the USB ports of my Mac?

Some manufacturers use a blue insert to designate a USB 3 port or device. All USB ports on Mac computers that support USB 3 are USB 3-capable and don't have blue inserts.

What USB 3 devices are supported?

All devices that conform to what is commonly referred to as the "2008 version 1 USB 3.0 specification" are supported.

Are USB 3 hubs supported?

Hubs that conform to what is commonly referred to as the "2008 version 1 USB 3.0 specification" are supported.

How do I get the best performance from the USB 3 ports?

The first device you plug in will configure the port, so always connect USB 3-capable hubs or devices first.

What happens if I plug in a USB 2 device into the USB 3 port first?

If you plug in a USB 2 hub first, all devices connected or "daisy-chained" to that hub will operate up to the maximum transfer rate of USB 2 speed (480 Mbps).

What happens if I plug my USB 3 device into a USB 2 port?

Your device should be backwards-compatible with USB 2 ports. However, you won't get USB 3 speed and power may be limited to 500mA.

Is USB 3 supported in Windows 7 and 8 using Boot Camp?

Yes. USB 3 is supported natively in Windows 8. See Boot Camp: Frequently asked questions about installing Windows 8 for more information.

To implement USB 3 support on Windows 7 using Boot Camp, download and install the Windows Support Software (drivers). See Boot Camp: Installing Windows 7 Frequently Asked Questions for more information.

Are there differences between USB 3 cables and other USB cables?

Yes. USB 3 cables:

  • Use more wires than other USB cables. This makes USB 3 cables a bit thicker than other USB cables.
  • Usually have a blue insert.
  • Have an "SS" symbol on the computer connector.
  • Use a different connector on the device end than USB 2 cables.
  • Can deliver more power to an attached device (900mA).

Can I use a USB 2 cable to connect a USB 3 device to my computer?

If the device end of the cable fits into the connector on the device, yes. However, because it has fewer wires, you won't get USB 3 speed and power may be limited to 500 mA.

Fixing issues with USB 3 devices on your Mac

Use this information to fix any issues you might have while using USB 3 devices with your Mac.

How can I determine if my device is connected as a USB 3 device?

Use the System Information utility:

  1. From the Apple menu, choose About This Mac.  
  2. Click System Report.
  3. Under the Hardware heading on the left side of the System Information window, click USB.

System Information

USB 3 devices appear under USB 3.0 Bus, and USB 2 devices appear under USB 2.0 Bus. Click the device names to learn more about each one.

Why do my USB 3 devices seem to only work at USB 2 speed when I use virtualization software on my Mac?

Some virtualization software doesn't yet support USB 3. Contact the manufacturer of your virtualization software for more information.

Why don't some USB 3 devices activate or appear on the USB 3 bus?

Try these tips if a USB 3 device doesn't activate or appear on the USB 3 bus:

  • Be sure you've installed the latest software updates available for your computer. To check, choose App Store from the Apple menu and see if any updates are available.
  • Sometimes unplugging and plugging the device back in can resolve the issue.
  • Try plugging the device into another USB port on the computer.
  • Check to see if a firmware update is available for your device from the manufacturer.
  • If the device came with an AC adapter, use it.
  • Restart your computer.
  • Try a different USB 3 cable.
  • Try a different USB 3 hub.

Why do I have difficulty with Wi-Fi or Bluetooth devices when USB 3 devices are attached to my computer?

Some USB 3 devices—hard drives in particular—can generate radio frequency interference that can cause Wi-Fi and Bluetooth devices operating in the 2.4GHz band to have issues communicating with your computer.

Don't place hard drives or other USB devices behind your Mac, or near at the hinge of your screen. The antennas for Wi-Fi and Bluetooth are located there, and USB 3 devices placed there may interfere with your wireless connections.

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