Some USB keyboards and mice, and some ways of plugging them into the system, can result in noticeable issues like key ghosting and input lag. Thus some people s

Some USB keyboards and mice, and some ways of plugging them into the system, can result in noticeable issues like key ghosting and input lag. Thus some people still kept around their PS/2 devices and avoided USB adapters. This is mostly not a problem nowadays. The issues arose from cheaper/poorly implemented devices and the use of hubs (both internal and external) to provide more ports.