When in the 90's? I'd expect it would have taken the full 2x 42U racks to keep the whole dataset in memory at one time. Not to say it's required, but that doesn't sound totally crazy for the time period.

Also, having an order of magnitude more hardware than you ought to need is totally understandable when hardware capability is increasing by an order of magnitude faster than hardware replacement cycles. It's when you're off by several orders of magnitude that it starts to become suspect.