The 6400 has 8MB on the motherboard, takes 2x64MB EDO DIMMs for a max of 136MB.
The 6500 has 0MB on the motherboard, takes 2x64MB EDO DIMMS for a max of only 128MB.
The 6500 has 0MB on the motherboard, takes 2x64MB EDO DIMMS for a max of only 128MB.