[Beowulf] Is there really a need for Exascale?

[Prentice Bisbal]

On 11/28/2012 02:17 AM, Mark Hahn wrote:
>
> as heretical as it sounds, I have to ask: where is the need for exaflop?
> I'm a bit skeptical about the import of the extreme high end of HPC -
> or to but it another way, I think much of the real action is in jobs
> that are only a few teraflops in size.  that's O(1000) cores, but you'd
> size a cluster in the 10-100 Tf range...

I don't think this heretical. I think it's a perfectly legitimate 
question we should be asking ourselves. Such a discussion can open a big 
can of worms on this list, and should probably be it's own thread. I've 
got too much work to do today, so I can't weigh in as much as I should, 
but I will change the subject of this reply to start a new thread on 
this topic.

I frequently make analogies between HPC and car racing, usually F1 (John 
Hearn's ears just pricked up!). In this case, Exascale is auto racing, 
and the rest of the HPC world is regular computing. Manufacturers say 
that competing in autoracing allows them to develop and test new 
technology that will eventually trickle down to their passenger 
vehicles. You could argue that Exascale is the same thing. Sure, it's 
impractical and expensive, but it creates R&D opportunities and allows 
this new technology to be proven in real use before it trickles into 
"consumer" products. And then, there's the "Win on Sunday, sell on 
Monday" effect, which I don't think needs any explanation.

A more cynical view would say that it's just a huge pissing contest 
between different vendors,or countries, or national labs, or 
universities, etc.

An even more cynical view say that the HPC vendors lobby the government 
to believe exascale is important so the government invests in it and 
subsidizes their R&D.

In my opinion, the new technology driven by the move to petscale, 
exascle, etc, will ultimately valuable to use consumers, but to your 
average researcher, having a decent-sized cluster that they have a lot 
of access to is more valuable than a large, shared system like Blue 
Waters or something similar, that must shared with hundreds or thousands 
of other researchers. It all comes down to FLOPS/year that they can 
actually use. Yes, this ignoring capability computing situations where 
you MUST have a super large cluster in order to run a really large job.

--
Prentice