Another question then

my system is a Athlon 3000 + AMD running at 2.16Ghz and 512 Mb mem with a Nvidia Geforce4 mx 440 se vid card and a couple of hard disks , what sort of frame rates should i be reliably getting guys , i had it locked on 44fps but at times it dropped right down and things got jerky , so now its locked at 25 fps , i have everything maxed out , but do i really need it all maxed out what could i turn down without loosing too much detail and realism , i mean whats the ideal settings if there is such a thing