The SE\30 has 2 banks of RAM to fill with, Bank A and Bank B. Bank A needs to be filled first, filling Bank B and leaving Bank A empty will not work on the SE\30 (and the other Mac II series).
So, using:
256KB SIMMs on Bank A only gives you 1MB, and on both Bank A & B gives you 2MB.
1MB SIMMs on Bank A only gives you 4MB, and on both Bank A & B gives you 8MB.
-- (Up to here you do not need Mode 32 or 32Bit Clean ROMS) --
4MB SIMMs on Bank A only gives you 16MB, and on both Bank A & B gives you 32MB.
-- (This is enough for most people... You will need Mode32 or 32bit Clean ROMs) --
16MB SIMMs on Bank A only gives you 64MB, and on both Bank A & B gives you 128MB.
-- (PROBLEM HERE! They should be EDO 16MB RAM BUT Not all 16MB EDO RAM works in the SE\30 & Mac II Series. You need to test it out to see if it does work or not with your machine.) --
Things to know:
Do not Mix RAM in a Bank. Make sure they are of the same type, maker and speed.
You can mix Banks of RAM to get in between RAM sizes, like 1MB RAM in Bank A and 256KB in Bank B to give you 5MB. But if you do this, use the larger RAM in Bank A first and the smaller RAM in Bank B. And they should be of the same speed RAM.
The More RAM you put into your machine, the longer it takes for it to boot up because the RAM Test takes longer to do. As high as 12 or more minutes for 128MB of RAM.
This answers your questions?