In a past life all serious scientific computing was handled by many nodes in a blade server array. Mac was never on the table for anything serious....
Just teasing as I write this on an Ipad.
Right ... different types of computing ... heavy lifting is on a Linux based cluster (the really heavy hitters often choose to distribute workloads literally globally via the open science grid). I have private local access to a machine with 10 dual-quad nodes, with 16GB of RAM each and ~ 4TB of raid duplicated global disk. Actually, it's getting a little long in the tooth, but still serves well. On a laptop I need to be able to do programming, access Linux command line utilities, run lightweight jobs, write documents in LaTeX, and ssh remotely into the big machine, etc. It's not power that is vital in this case, so much as "culture". There are ports to Windows that work OK for a lot of that, but nothing really compares to having a Unix-based OS native under the hood.
