By: Emil Briggs (me.delete@this.nowherespam.com), October 20, 2012 4:52 am
Room: Moderated Discussions
> I'm constantly being asked to show why I think
> these machines are a waste of money. I'll turn the question around. Will
> someone please explain why, when my desktop could have designed the space
> shuttle, you now need a warehouse full of cabinets to do much less? Your answer
> appears to be a long line of scientists who are unsurprisingly lined up to get
> on the fast track to fill the journals with junk--so they can get tenure.
>
Just for reference. I'm not anonymous and I could care less about tenure.
A lot of supercomputer time gets used for density functional calculations. And it has produced valid and useful results that are interesting both commercially and from a pure science perspective. Indeed such calculations have helped produce that desktop that you talk about since a detailed understanding of the physical mechanisms involved is important to improving semiconductor processes.
And there are DFT methods that scale well computationally on supercomputers. A bigger limitation is that most DFT methods exhibit O(N^3) or worse scaling with the number of atoms being simulated which limits things to a few thousand atoms on the current generation of supercomputers. To study larger systems (and there are plenty of commercial and scientific reasons to want to do so) will require new algorithms.
