I have to disagree; disk is ancient - it's mechanical egads! - while 10GigE is pretty commonplace now and infiniband and fiber channel are even faster.
back from my CS 101 takeaways: there are only 3 bottlenecks in a computer system: CPU, network, and IO.
looks like MemSQL is fixing the CPU and IO bottlenecks, but physics is physics so network is pure hardware solution haha