Lightweight firewall which does not slow down the system?

I used outlook until today, because I was quiet happy with the firewall, until I figured out that it slows down very much the server (web server with lots of traffic). Page loads doubled in time.
I tried only so far comodo (VERY slow with lot of server access from the internet, good for personal computer), outpost (slow too), kerio (not 100% compatible, had problems).

What (freeware prefered) firewall would you recommend which does not slow down much the system (consider it is a server, where it has to filter/check a lot of packets all the time)?

 

Search the forum for CHX-I 3 , robust, Ghostwall, stateless but light (official forum here). Why a Windows server may i ask?

 

I am trying at the moment PCTools Firewall. It almost does not slow down the server, pages load now twice as fast as before with outpost...

Why windows server? Because I work since ever with Windows OS (since they exist), and program on Windows OS, so its easier for me to maintain or fix if something is wrong...

I will check the firewalls you mention in a moment. I heard about Ghostwall, but never about CHX-I 3.

Thanks for your advice!

 

Online Armor free is very light. Only about 14K with both services running that it uses.

 

Just a quick note: CHX-I 3 and Ghostwall don't have application control.

 

Jetico I, free, very light and has application control and a limited HIPS function.

 

Ghostwall and Online Armor are two good firewall and wich are lightweight...

 

Try Sygate 5.5 Free. I'm not sure how it behaves on a server, but it is very light for a normal system. You might have a pleasant surprise

 

Use Jetico Firewalls 1(if you have no stability issues with it,free though) or version 2(its payed).
I tested a lot of firewalls and lighter than Jetico i never saw.