Re: [lwip-users] How to optimize raw UDP performance

[Chris Strahm]

Actually someone else reported to me that turning the checksum off in lwIP
actually made it slower.  I have not checked the reason for this, but that
was someone else's experience.  There is a big difference in whether you use
8/16/32 bit memcpy type routines.  Also if you can write it in asm.  Since
yours is FPGA, little different.  Also same kind of thing for checksum.  Asm
will be faster.  Sometimes the difference in how a particular variable or
address pointer is generated by C can result in very big difference in code.
You have to look at everything when it comes to high performance.

Also what is the size of your PBUFs and your blocks in your DMA or MAC ISR.
I assume for a 1G Enet system you probably want the maximum, about 1536
each.

Chris.