I didn’t read the entire poll -sorry if anyone has talked about this before.
I ve been having the same problem for over years, and I couldn’t get any efficient render with dbr until today. My situation was like this:
Single machine renders the scene in 45 secs while 2 or more machines render it in more than a minute. The apparent reason of the latency is an irrational delay in the finishing of certain buckets. I say irrational because those buckets -which take for instance 30 seconds to finish- are normally rendered by both machines (when each machine renders alone) in less than a second.
More than 90% of my DBR renders were taking more time to render, than a single machine render attempt.
My network was composed of gigabit ethernet cards, which are connected through a 100 mbit router. Today I ve bought a gigabit switch and connected the cards through it. I retried DBR. The results are surprising.
All my DBR attempts decrease the rendering time as it has to be. Addition of extra servers to render speed is directly proportional to the server’s cpu speed. It dramatically increases render speed in both single frame or animation rendering.
Network delays seem to be the reason of this delay in rendering of certain buckets.
DBR gained a meaning right now.