I am going to build a Server that is going to be located in a co-located server farm.
I have decided that I will use Red Hat 7.2
On the Red Hat internet site it shows the Performance Tuning tab, what I would like to know is the setting I should use for Max Connections, as I want to be able to handle as many requests as possible.
I have not built the Server yet, but it will most probly be a P4 1.6 GHz with 512 Mb Ram etc. The Net Connection will be 1Mb Fibre.
Any ideas to what level I should set the connections to? And is there any other setting that I could change to make full use of the hardware and connection?
Finaly, how can I calculate the amount of unique users that I will be able to serve over a sec or over a certain time frame?
I am sure that you have already seen This Document [redhat.com] it is probably as good a place to start as any. There are many factors that can affect what the settings should be, the ones they recommend are usually adequate. Most performance tuning is a trial and error process, I wish I could give you a formula based on your cpu, memory, and bandwidth, but I can't, I can say that most often the defaults are adequate.
You can gradually change them over time to get the most out of your setup once you know your traffic load and content makeup better. Some page designs and server side techniques naturally use more memory and cpu, graphic intensive pages use more bandwidth, all of these factors affect the length of sessions and how long a process lives, which all affect how many sessions you can sustain.
IMO you can only find the correct balance through load testing [google.com] with actual sites to be served prior to going live, or if you're more adventurous, after the server is up and running :)