Q: Are there any mobos that can actually handle that much? If not, What's the limit? And do you think I could make money by making custom computers for the neighborhood, and upgrading other computers too?
A: The current max is 16GB but this is really due to the space limitations of most motherboards and the maximum DIMM size available. Most motherboards only support 4 DIMMs each of which can be 4GB DIMM and some will support the 16GB total, but lets be realistic, why? 8 is the common maximum and it is more then enough 100% of the time, there really is very little reason to even have 8GB of ram let alone 128GB or even 16GB.