TCP Tuning Guide

Version 1.0 - Last published Jun 1, 2009

System Tuning

TCP Background Linux FreeBSD Solaris Windows XP Windows Vista Mac OSX Other

More Info

Data Transfer Tools TroubleShooting NIC Issues Duplex Issues Application Tuning Tools More information

Publications

O'Reilly Article Usenix Article Tutorial

Mac OSX Tuning

Mac OSX tuning is similar to FreeBSD.
sysctl -w net.inet.tcp.win_scale_factor=8
sysctl -w kern.ipc.maxsockbuf=16777216
sysctl -w net.inet.tcp.sendspace=8388608
sysctl -w net.inet.tcp.recvspace=8388608
For OSX 10.4, Apple also provides a Broadband Tuner patch that does a less aggressive version of this for Mac OS X 10.4.

Starting with OSX 10.5, Apple added "self turning TCP", and increased the default maximum socket buffer to 8MB, a much more reasonable value.

More information can be found at this OSX Network Tuning Guide.