We upgraded one of our inbound mail servers from RELENG_4 to
RELENG_5. Hardware is the same. Its possible there is a measurement /
reporting issue, not sure
http://www.tancsa.com/upgrade.html
But on the box, it does "feel" faster even at what used to be peak times in
terms of responsiveness-- especially how it now handles big blast of spam.
So it sort of backups up the numbers from that standpoint.
Neither box was overly optimized. Apart from pulling some unused drivers
out of the kernel configs, they were both essentially running GENERIC
---Mike