Newbie 3000+/Syntax K7S746FX Q

Just built a new PC with an Athlon XP 3000+ and a Syntax K7S746FX
motherboard (SiS northbridge/southbridge, I believe).

Initially it was mis-identifying the CPU as an Athlon XP 2200+, but I
found the setting (changed CPU frequency from 133 to 166) that sorted
that out.

I'm still not sure everything is running properly. The graphical
"Syntax" logo stays on the screen at boot time for 30 seconds or more,
and normal operations in Windows (XP Pro, clean install) feel
sluggish. Especially just opening windows, closing them, etc.

The video card is a GeForce FX 5200 w/128MB (AGP). 1 GB of PC2700 DDR
SDRAM.

Any suggestions?

Thanks in advance!

--chris