Mitsu, same conf here, but using K7 700Mhz instead PIII 800 (GF3 is Ti500), sheep have no impact at all (1280x1024x32bpp, same as desktop, and no AA effects). Perhaps you may try older drivers for the GF3, I found the newest ones very crappy and slow compared to those of four months ago.
Two more tips:
1 - Be sure to have the fastest drivers for your chipset (not just the latests) and AGPx4 enabled for GF3.
2 - Set AGP aperture size to 256 in bios setup.
