That site is a bit questionable. I entered "64TB" as the answer and it was very happy to show me a bunch of servers that maxed out at 6 or 8TB. Even the one server that listed 64TB of RAM might be questionable since it's not leaving room for the OS or your applications. That said 64 TB is a gargantuan amount of data, so I'm not too worked up over it not fitting in RAM. Lord help you if you have a power outage and have to reload the data from disk.