That's not always the case. My last three laptops have the RAM hanging off the edge of the mainboard. The SO-DIMM connectors are where the board stops, and ther

That's not always the case. My last three laptops have the RAM hanging off the edge of the mainboard. The SO-DIMM connectors are where the board stops, and there's "nothing" under the modules. The CPU is actually in the middle of the MB, close to the two edges (top and bottom), but the cooling fan and heatsink are to one side, connected via some heat pipes.