USB devices slowing other ports down

There are three USB2.0 ports on my computer. If I have the external HDD as the sole device on the computer, I’m getting 18MB/s, but if I have a hub with attached printer + memory card reader, the HDD slows down to 10MB/s even when the other devices are not in use.

Why does this happen?

Usually there are two (or more) USB sockets run off each controller. If you look in Device Manager (assuming you use Windows) you should see several USB Root Hubs listed. You may be able to improve performance by switching the HDD to a different port.

Its the crux with usb…
The slowest device slows all others down too. :frowning:

Keep in mind that USB is a Serial bus and the more devices you have at the same time the slower each one goes because its a shared bus. Switching to a different HUB is a good idea to try but in the end there is never a guarantee on top speed on all devices.