memory upgrades

[rbriber at POLY1.NIST.GOV]

We have a Iris 4D80GT running 3.2.0 with 16 megabytes of memory.  The memory
is in the form of 16x1 megabyte SIMMS on the system CPU board which is now 
full.  We have heard two conflicting reports about adding more memory.  The
first is that once this board is full we need to buy a new board for memory
(many $) and install the new memory on the new board.  We have also heard
that we can remove the 16 1 Meg SIMMS and replace them with 8 4 Meg SIMMS to
give us 32 Megs and still have the possibility for adding more memory in the
future.  Even though we loose the 16 1 Meg SIMMS the method of upgrading
to 4 Meg SIMMS is significantly cheaper than buying another board.  Does
anyone know whether the system architecture will support this swap?  

Also does the kernal have to be reconfigured after the memory upgrade or
will the system figure things out on it's own after adding the new memory?