Honored Contributor
Honored ContributorThroughput is dependent on many things - both NIOS II system related things and lwIP build/options related things. There are many things you can do to improve performance - somewhere in this thread IIRC I listed them in what I perceive as the order of importance.
All of our lwIP based NIOS II products have high performance requirements. One was Gigabit and required high transmit bandwidth and TCP couldn't be used so we used our own reliable UDP protocol. We had no problems with 500Mb. The latest product is GigaBit too but performance for receiving is important. We have better performance to run 10/100 over 1000! We have 40Mb throughput and this is far more than we need so no special protocol was used. But in all of these systems internet checksumming is done in the FPGA (Cyclone III). This 40Mb is an effective average rate for us - let me do a test for sustained receive bandwidth and I'll post back here. So to correct you, receiving is harder (slower) than sending - by quite a bit. And remember, the more you do to improve TCP/IP speeds the less time the NIOS II has for other tasks. You can probably do 80Mb receive but you'd have no time to do anything with the data. :) High speeds can be achieved but you may have to do a lot to get there. Bill
