upgrading processor

I am in the process of upgrading my main rig, I have already put in a gigabyte ga7n400el nforce mb, gigabyte 9600 pro, silent boost hs and fan, and want to buy new ram and cpu. I have in there now a 2400+, gig of ddr 2100, I want to buy a 3200+ but don't want to fork out all that money all at once for ram and cpu. Will the 3200+ run on the 2100 ram for awhile until I get enough money saved up or am I wasting my time and maybe should rob the bank and buy it all at once? Thanks in advance.

 

Yes the new cpu you want to use will utilize the pc2100 memory, but obviously it won't be able to run at the board's fastest clock speed.