As found in the Dell Performance 425x/ME, machines in this series can have a maximum memory capacity of 128MB, a total of four memory slots and no removable base memory. The slots are arranged in two banks, containing two memory slots each.
The second available option is seen in the Dell Performance 425s/M. It has a smaller maximum memory capacity of 64MB. Like the first configuration, it also has four memory slots. These slots are arranged in four banks of one.