Bad FPS in consol (Best Windows ??)

[cocoon06]

Hello,
I have a server BI-Xeon 2 x 3.2 GHz Dual-Core Intel DP 5060 with 2 GB ram DDR 2 667 MHz ECC.

I have a strange problem, because FPS of my server at 500 but in my consol when i write stats i have between 100 to 200 FPS.
It's unstable and the server is not very very good quality.

http://www.chaleurverte.be/srcds/fps.jpg

Some people has have this problem ?

The server don't have plugin.

OS: Windows server 2003 (without service pack)

What is the best windows for srcds ?
Windows serveur 2003 R2 SP2 enterprise ? standard edition ? web edition ?

Thank for you help

[Drocona]

I have no idea why that would show up like that, my FPS is always 512... even in stats

There is no "best" windows, I always use a stripped version of WindowsXP Professional and it works like a charm.