Question : Would four 1GB sticks of memory work better or 2 of 2GB sticks

I have a dell precision workstation 490 and it has 4 banks of 2 slots for a total of 8 banks.  But I am only running a 320bit OS so I was to upgrade up to 4GB of ram.  It currently has 2GB installed with two 1GB sticks in one bank of 2.  

So to do the upgrade to 4GB should I just throw in another 2 sticks of 1GB or pull out the two sticks of 1Gb and put in 2 sticks of 2GB?

Which would be better performance?

thanks in advance

Answer : Would four 1GB sticks of memory work better or 2 of 2GB sticks

Performance difference would be negligible if they are the same speed sticks you have.  If you ever plan to upgrade to 64bit OS, I'd use the 2GB sticks - otherwise, whatever is on hand or cheaper for you.