at the time the original xbox was designed and its same generation of intel CPUs, the absolute practical maximum you would be able to put into a single socket d

at the time the original xbox was designed and its same generation of intel CPUs, the absolute practical maximum you would be able to put into a single socket desktop motherboard would be 768MB of PC100 or PC133 SDRAM (3 x 256MB DIMMs). If you actually saw a system with 768MB of RAM in it, that would be some very high-end CAD workstation. There was no practical way to get anywhere near 4GB of RAM within the dollar cost that a person purchasing a $200 CPU on a $150 motherboard would be able to bear.