Hi-Speed devices are intended to fall back to the slower data rate of Full Speed when plugged into a Full Speed hub. 9L0-509 Hi-Speed hubs have a special function called the Transaction Translator that segregates Full Speed and Low Speed bus traffic from Hi-Speed traffic. The Transaction Translator in a Hi-Speed hub (or possibly each port depending on the electrical design) will function as a completely separate Full Speed bus to Full Speed and Low Speed devices attached to it. This segregation is for bandwidth only; bus Apple 9L0-402 rules about power and hub depth still apply.
A hub will have one or more Transaction Translators and there is no standard way to determine the number of transaction translators a hub may have. All low and full speed devices connected to one transaction 9L0-509 translator will share the low/full speed bandwidth. This means that hubs can have dramatically different performance depending upon the number of transaction translators and the devices plugged into their ports. e.g. a hi-speed 7 port hub with only 1 transaction translator with 7 low/full speed devices plugged in, will act no differently than a USB 1.1 hub and all devices compete for the same low/full 9L0-402 study guide speed bandwidth. If the hub were to have a transaction translator for each of the seven ports, then each device would have all the full/low speed bandwidth available to it and would only compete for the hi-speed bandwidth, which is much greater.
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