Do not be afraid to do the fsb freq mod.
It is very simple.
Sure you run a slight risk, but if you do any mod such as unlocking CPU, you also run a risk of damage.
I would much rather do this mod 10 times than unlock one XP Palamino.
To put it simply, the factory removed the 3 pin jumper for manual settings, and added a wire (staple)
to connect 2 of what would have been jumper pins. Simply cut the wire (staple), or unsolder if you are
capable, and connect the center pad to the other pad that was not used. To connect the center pad
to unused pad, some use conductive pen, others use solder. Basically, you could use whatever you
would use for unlocking CPU's. I simply removed the staple and added a 3 pin jumper from an old
modem, so I could then switch between manual and jumperless settings. Or you could just remove
the staple and put it back in other position.
After doing the mod, if your CPU is also unlocked, you do have control over multiplier.
There is no vcore adjustment in bios, so if you want to change CPU vcore you will need to do that with
L11 bridges on the CPU.
My XP1600+ is now running nicely at 155MHzx10.5, and using onboard graphics hits 2200 3dm2k1se.
EDIT:
Forgot to add, mine was a Newegg $49 Refurb, and I will be buying more. Excellent boards!