Most dual E5 motherboards have 16-24 DIMM slots, 32GB DIMMS exist but are insanely expensive and big, most likely they would use 16GB DIMMS so they probably hav

Most dual E5 motherboards have 16-24 DIMM slots, 32GB DIMMS exist but are insanely expensive and big, most likely they would use 16GB DIMMS so they probably have 256-384GB of ram per box. They could in theory be using some custom motherboard shenanigans to increase the capacity, but that is unlikely. Keep in mind that the CPU's they mentioned are ~$1600 each in lots of 1, I'm sure they are getting a good discount for volume but that is still a lot of $ per box in CPUs, I would imagine they need to pack them full of VMs to offset their costs.