It is difficult to determine the exact performance of the port controller because there are so many differing factors which all influence the final figure. Amongst others there are:
The performance is usually measured by the time the FIQ is active in dealing with a mini-burst of eight back to back cells on a circuit which is sending regular mini-bursts. A substantial number of samples are taken and averaged. The performance is based on the time and the number of user data bits passed - that is on the forty eight octets only.
Performances have been observed of more than 52 Mbits/sec for an Arm 3 and over 68 Mbits/sec for the Arm 600.