[OT] jumper for CPU Host Clock

[jh]

Hi. I am building my computer today and have a question about a jumper 
setting. I need to set the jumper for the CPU Host Clock Selection and I'm 
not sure what this refers to. There are two choices, 100MHz and 133Mhz. the 
133Mhz has a asterisk by it that says Reserved. Does this refer to the kind 
of SDRAM I'm using? I am using PC 133 SDRAM 32x64 168 pin DIMM. The 
processor is an Amd Athlon 700MHz slot A. Thank you for your time. -Jeff H