best server setting

how to tune the server be the best for loading http???
my server is P3 866 with 512RAM
using Linux 7.0

it is my settings in my server now~

Timeout 20
KeepAlive Off
MaxKeepAliveRequests 0
KeepAliveTimeout 15
MinSpareServers 100
MaxSpareServers 100
StartServers 100
MaxClients 100
MaxRequestsPerChild 0

I still think its efficiency could be enhanced...
Thanks for any response...or advice...

>> how to tune the server be the best for loading http???

On top of that, there are still many dependencies you failed to provide (i.e. how many users, what other daemons running)

Why you KeepAlive Off?

The following can handle roughly 3000 - 5000 users:
StartServers 100
MinSpareServers 35
MaxSpareServers 75
MaxClients 512
MaxRequestsPerChild 20000
rlimitcpu 90 90
rlimitmem 50000000 50000000

1.KeepAlive Off

for the reason of speed- as http to the page will be very slow if it is on(i tried it on before and do not know the reason)

2.supposely my visiters are daily 100,000 to 200,000 (I hope)
How the settings are..

3.any trade off for the settings you suggested and my currently used settings.

>> for the reason of speed- as http to the page will be very slow if it is on

No. If you wanted to optimize your server, you should enable it. Setting keepalive off is a waste of bandwidth, really waste. KeepAliveTimeout 15 is fine. If your server runs out of httpds, increase the number of httpd and lower the number of Keepalive timeout, but never disable it.
The setting I provided can handle well over 300,000 requests. The 5000 users I mentioned previously was referring to number of sites on your server. You might want to get more memory, 1GB or more is not uncommon as the price is damn cheap these days.

>> any trade off

You still haven't provided what other daemons you are running on the same box.

If you really wanted to maximize the performance, don't run Linux, run FreeBSD.