Hi,

Not sure if others were already aware of this tweak, but in the BIOS/cyclone of your cats box there's an option called fclk.  It seems that fclk controls the clock for the footbridge.  This clock also drives the clock speed for the memory.  by doing:
set fclk 66
in the bios I got a 32% increase in memory bandwidth.  From what I can tell the bios defaults to 50MHz.

Obviously you need PC66 DIMMs.

Just thought I'd share this little gem.

Chris