Howdy;
Some points of interest you might consider but aren't really what you're asking. I don't have anything compatible to help give you an idea of an acceptable playability level (bench mark) for your machine but ...
System Resources - Check your task manager to see what's loaded and running in the background before starting your game. You might want to consider stopping some of the services on your machine depending of course on what's loaded. Everyone manages their environment differently so going into detail probably won't help. If it were me I'd want to know what services are running, why they are running, and why I haven't shut them off.
Memory - I was told that matched sticks of memory are always the way to go when more than one memory stick is in use. So matched pairs like two 512 sticks or two 1 gig sticks both with the same speed 5ns etc are optimal. I only mention this because 784 in any configuration I'm aware of is unmatched. Love to hear any views on this if anyone has any.
Front Side Bus - I'd say the most limiting factor of your machine is the FSB. In your next upgrade or purchase spend the extra cash if able for an 800 or Gig FSB. Again I'll say I've never played WOV on a machine like yours that I can tell you if this is the problem. I only make mention of the FSB as it's the bottleneck in most configurations where demand is high.
AGP Apature Size - I'd check your system bios to make sure your machine is set for the 256 AGP Apature Size, or matched to your card (ie 128 to 128 etc) Settings that don't match here can really slow your machine to a crawl. If you're in doubt of your card's size, check the Manufacturer's Site for details.
**Note: All information above is to be considered helpful advice. There are many members of the community more qualified to help than myself I'm sure, hopefully they'll chime in and correct my errors or thinking as necessary.
**Subliminal Message** B*U*Y**A*L*I*E*N*W*A*R*E **
Take care;
Erik