Comparison of FreeBSD/Linux TCP Throughput performance
gnn at neville-neil.com
Sat Oct 17 20:36:42 UTC 2009
Trying to chime in with a few pointers here. Things to check when
doing a TCP benchmark on FreeBSD.
In particular make sure to adjust theses:
Leave the auto on, but increase the max values and you should probably
also change the inc (increment)
values as well. Make sure that if you increase the buffer sizes you
increase your number of mbufs and
clusters as well. See kern.ipc.nmbclusters, which is a kernel tunable
that can be set in /boot/loader.conf .
Make sure that both of the systems you're testing have the same low
level hardware support such as
TCP Segment Offload (TSO) and TCP Checkusm Offload are turned on.
Also you might want to turn this off:
This page http://fasterdata.es.net/TCP-tuning/FreeBSD.html
claims that it can harm high speed connections.
Those are the basics to start with. A search of "Tuning FreeBSD TCP"
turns up some decent pages as well.
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