Broadband Tuner 1.0

About Broadband Tuner
The Broadband Tuner allows you to take full advantage of very high speed Internet connections that have a high latency (5 Mbps or greater). The installer tweaks some system parameters.

There is an optional uninstaller that can be used to restore the settings that were in effect at the time just before the system parameters were changed.

What does the Broadband Tuner do exactly?

The installer increases the default values for the size of the TCP send and receive buffers. With larger buffers more data can be in transit at once. A startup configuration file is also updated so that these changes will persist across restarts.

The system parameters are sysctl variables that are set as follows:
net.inet.tcp.sendspace: 131072
net.inet.tcp.recvspace: 358400
kern.ipc.maxsockbuf: 512000

This change has a system wide effect and is applied even if the network is not high speed connection with a high latency, with the exception of modem connections for which the system uses small default TCP buffer sizes.

So, has anyone tried this and noticed any speed differential on their system?

I ran it on my iMac G5, and it "seems" to be zippier. Could be just my imagination or wishful thinking. At least it didn't break anything. I'm still waiting to install the new security update.

I haven't been able to tell any difference one way or another.

I have seen a difference with the Security Update and the RSS screen saver - when I lock my screen and the screen saver comes on, it no longer shows "Press the <number> key for more". It still shows when the screen saver kicks in automatically and I don't lock the system, though.