The examples mentioned are the web (50B nodes, 1000B links) and the Facebook social graph (0.8B nodes, 100B links).
You might fit quite a bit into a beefy 3TB RAM server, but it might not be the best ram-to-cpu ratio for graph algorithms.
You might fit quite a bit into a beefy 3TB RAM server, but it might not be the best ram-to-cpu ratio for graph algorithms.
I would imagine real biological data isn't quite there yet, but it's certainly not for want of trying. Simulations might get pretty close. Blue Brain was aiming for 100M neurons and (presumably) a few orders of magnitude more connections and I think there's another simulation floating around with 10^11 neurons (but presumably less biophysical accuracy).
But yes, assuming your data is "big data" when it can easily be processed on a dev workstation or beefy server is very much in vogue right now.