From: "Duncan Brinsmead" <dbrinsmead@alias.com>
Subject: RE: Speed up rendering times for fluids
Date: Mon, 15 Dec 2003 14:52:03 -0500

Here are a few tips off the top of my head.

1. Set the fluid shading quality as low as you can without getting dots.
  Avoiding hard edged boundaries, particularily thin shell elements
  in the fluid can help one avoid needing a high quality setting. 
  One should avoid sudden transitions in the opacity graph or very 
  high frequency textures, for example.

2. Avoid the billow texture(very slow).. instead use perlin or 
  spacetime( if textureTime is animated ) with inflection on.

3. If you don't need it, turn off self shadowing for the fluid.

4. If you are casting shadows from objects onto the fluid use depthmaps, 
  not raytraced shadows.

5. If you don't need shadows from objects onto the fluid, turn off 
  recieve shadows on the fluid( note that it can still self shadow 
  when doing this ).

6. If you are raytracing, particularily if you have multiple fluids 
  you may wish to turn off casts shadows on the fluid.

        Duncan