A USB (Universal Serial Bus) host controller, a corresponding integrated circuit chip, a computer system and an operation method are provided for handling the data traffic between at least one USB device and the computer system having system memory. A transaction processing unit processes transactions to or from the at least one USB device. Further, a transaction duration management unit is provided for determining estimated duration values of the transactions. The transaction processing unit is adapted to process the transactions dependent on the estimated duration values. A descriptor-to-transaction converter may be provided, and the prefetched mechanism may be made dependent on a threshold value relating to the estimated duration values.