Athlon 2400 (or 2600) on Asus A7v266

[Upgrade for Asus A7v266]

Hi guys,
I would like to here your opinion:

I'm consider to upgrade my AMD Athlon 1800 to Ahlon 2400 or Athlon 2600.
I have A7V266 MOBO , revision 1.06.
Asus officially support those CPU modeles since revision 1.07.
I have installed the BIOS that should support Ahlon 2400 and Athlon 2600.
When I enter BIOS (with my unlocked Athlon 1800 ) the maximum multilier I can choose is 12.5/13.
From Athlon 2400 CPU spec I learned that it's multipler is 15.
Guys, that do you think will happen if I install Athlon 2400 ? PC won't boot at all ?
Will it run at original multiplier (15) or will it reduce it's value to 12.5 ?

And here is another question:
First and last options in Multiplier choice-list are shown like this:
5/14 x
12.5/13 x

while setting it - the PC use the lowest (12.5 and not 13 , 5 and not 14).
What does this slash mean ?
How may I force it to use the higher rate ?

[Greg]

I have managed to overcome this problem.
I installed Athlon XP-M 2800 on my a7v266 revision 1.06.
in order this to work I had to modify bidges configuration (cutting and closing) since this CPU default start-up multiplier is 6 and in this case my MOBO won't let me go higher then 12.5. It should be 13 or higher.
Regarding Athlon 2400 XP or Athlon 2600 XP, I guess no bridge cutting is required. BUT it is very important to set the so called Palomino jumper to
"Palomino" mode .