Congrats on your new purchase. Although you bought the dreaded P4 not too bad. If the AMD was an option, should have gone with that, bigger on chip cache and a faster processor overall. I have the XP 1600 and it would benchmark faster than the 1.8 P4 due to chip caches handeling of instruction sets.
You should however spend the $$ and get the approriate RAM for your system. Your 400Mhz FSB isn't really 400 unless you have the RDAM with the higher speed (800 or 400), I am going to assume that the RAM is PC133 or something along those lines ,which are much slower. The actual speed of the FSB is 100 or 133, plus the increased memory speed give you an effective speed of 400.
The only P4s worth getting, IMHO, are the new 2.0+ speeds (2.0-2.2 Ghz), increased on chip cache and changing the process core to .13 micron make it slightly faster than the much lower clock speed Athlon XP 2000 (1.67 Ghz).
