I am currently working on a lab application that is extremely sensitive to latency. We are using raw Ethernet frames (No TCP/IP, no ARP) as the communication channel, and currently our RTL8111/8168 GbE adapters have a few hundred microseconds round-time latency (point-to-point, no switches, etc).
Redesigning the application to make it more latency tolerant might be a better way, but for the time being improving Ethernet latency is our first priority. Do you guys have any experience on how to reduce the latency over Ethernet? Is it possible to reduce the round trip latency to less than 50us? Are there any special adapters/drivers designed for very low latency networking?
I do understand operating system has a strong impact on latency, so it could be just a magic kernel option that reduces latency dramatically... but I am not aware of any right now.
Any suggestions are greatly appreciated. Thank you!