Translations:Kernel/Gentoo Kernel Configuration Guide/48/en

Most systems come with two of the above interface types: EHCI (USB 2.0), plus either UHCI or OHCI (USB 1.1). To use USB devices, it is important to remember to select both types present on the system. While all USB 2.0 devices are backwards compatible with USB 1.1, a large proportion of USB devices (even the ones being manufactured today) are based on the USB 1.1 interface - why would a USB mouse need more than 1.5Mb/s?