Apart from what other commenters already said about the cost of software complexity, is there a variant of Amdahl's law that could be used here? 10x 100 GB servers working on a problem together will probably never be 10x faster than 1x 100 GB server. Perhaps just the increase in the order of magnitude of the distance information needs to travel is already sufficient to set some higher bounds... So you may need to buy more than 10 of them to match 1x 1 TB server.