how to reduce swaps

Hi

I am using ECC 6.0 version R/3 system (64 bit sap kernel) with 4gb of RAM size . 29 end users login to the system often . The swap rate is very high. Swaps are going on increasing for the specified buffers : Initial records,CUA,Screen,Calender and Export/Import.

So can anyone suggest me how to decrease the swaps and kindly let me the necessary docs to be followed

Moreover i want to know on what criteria the size of the buffers( initial Records,CUA,Calender) are increased and what could the maximum size of these buffers .

Regards

ganesh