A while back I recall reading rumors that China didn't even know what to process on their Tianhe-2. That kind of makes a supercomputer look like a pile of hardware, no matter how well it's organized or engraved.
[1] http://www.hpcwire.com/2016/06/19/china-125-petaflops-sunway...
Note that K computer (#5 system, Japan) scores 4.9% for HPCG. So Tianhe-2 and Titan are again 4x worse for HPCG compared to systems which score best for HPCG.
I don't think it's as simple as LINPACK bad, HPCG good. LINPACK is representative for some workloads, when compute dominates. HPCG aims to balance compute and memory. There is Graph500, if memory dominates for your workload.
By the way, K computer is #1 in Graph500.
The interconnect on the Sunway TaihuLight seems to be standard Infiniband, from reading other articles about the system.
I'd be interested to hear from someone who knows/has experience, whether any of the top 100 super computers ever have idle windows.
Having done exclusively HPC for almost 16 years now, I can state that there is one and only one immutable law of HPC: grad students will find a way to squeeze out every second of available CPU time on a large system. The amount of effort going into taking advantage of those empty spots in the clusters where smaller jobs can run quickly while the scheduler drains resources for a large job (called backfilling) is tremendous.
The thing that sticks with me is what a fantastically complicated problem HPC job scheduling is. I've seen dozens of fresh-faced undergrads or first year grad students come in with a full head of steam and decide that they're going to "solve" HPC job scheduling, but every single one has gotten bogged down in the minutiae and the muck, and I've never seen software that "gets it right". Every scheduler sucks in its own unique way.
Whether all of those jobs need an old-fashioned supercomputer is certainly up for debate, but they certainly get used, at least in my experience.
Or was it a combination of that with "well its there, and we want to do this thing that would happen quicker on the big machine" - IE not necessarily enabling new research, just adding a nice speedup to existing work?
So no, these machines are often used for problems which really do utilize the large-scale nature of the computers.
So lots of the "big data" type problems with lots of uncoordinated jobs aren't going to take advantage of the primary component of these big computers, the node interconnect. The computers really shine with big fluid dynamics simulations where there's lots of chatter between different components of the simulation to communicate boundary conditions and the like.
>> they certainly get used, at least in my experience
As a taxpayer, this made me feel good, thank you for sharing.
Kind of reminds me of when we heard a rumor than a rival ISP had bought a handful of Sun servers (in the year 2000). We thought they had tends of thousands of customers, figured they would be launching DSL, figured that had thousands of web hosting customers...
Turns out they got some weird grant so they spent the cash on those, otherwise they would have lost the money. They went out of business a year later and we kept chugging along with our Pentium III servers.
There are enough high quality universites in China to make use of it. I can not imagine this is true. There may have not been one big algorithm that it was built for, but university researchers always have stuff to compute.
That applies to most of supercomputers everywhere. "If you build it, they will come".
Besides the knowledge attained in building supercomputers ( which all major nations should know how to do ) and processor technology, the added benefits and new uses of these machines will come later.
The internet was created before people really knew what to do with it. The same thing with computers. The same thing with everything else.
The following paper compares the EU and US ensembles: http://journals.ametsoc.org/doi/full/10.1175/MWR2905.1
What matters most might be that China is maturing CPU technology that isn't nearly as congenial for US TLAs to hack in to. It might not matter so much for this supercomputer, but if Chinese suppliers put price ahead of things like opaque management processors, it might lead to tipping the balance away from easily exploitable endpoints.