Patent ID: 7536489

Claim:
An information processing system comprising: a high-speed serial bus that transmits and receives data independently over communication channels via a tree-structured network including a point-to-point connection; a first detecting unit that detects a first curve indicating a completion packet-to-payload size ratio T 1 /T 2 based on a time difference T 1 from when transmission of a request packet via the high-speed serial bus is started until a header of a completion packet corresponding to the request packet arrives and a time difference T 2 from when transmission of the request packet is started until a last completion packet of all target data is received; a time difference measuring unit that measures the time difference T 1 and the time difference T 2 , the first detecting unit configured to detect the first curve based on the time differences T 1 and T 2 measured by the time difference measuring unit; a second detecting unit that detects a second curve indicating a completion packet-to-payload size ratio A/(A+B) based on a header size A of the completion packet and a payload size B of the completion packet; a determining unit that determines a payload size for packet transfer based on the first curve and the second curve; and wherein T 1 , T 2 , A and B are real positive numbers greater than zero.