Its tough to say. First id load your project, and look under the main EASE window
under help *memory used*. If the prject is loaded and your under 50% id say that your ok.
If my machine uses about 400MB when its first turned on. I just loaded a large stadia model with about 3200 faces and it does just fine. My total used RAM went up to 550MB with the project loaded. Remember that ram will be used to store your program and your file, so the processor can access it faster. If my 3200 face file is about 2MB then I doubt the the NUMBER of faces will slow your machine down due to ram.
However RAM is cheap. So theres nothing wrong with 1 or 2 gig. Personally I use 2gig registered ram.
Whats your CPU speed, are you using a dual CPU setup. Iv always had VERY good results with dual cpus.