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Japan Captures TOP500 Crown with Arm-Powered Supercomputer

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Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#91

Post by jfkebwjsbx »

ChuckNorris89 wrote: post #57
Hamuko wrote: post #43

Earlier quoted context omitted.

Just how in the world are people deploying Django apps with DEBUG = True?

Simple, human error and no code review process for your production environment. Something similar happened to a huge retailer here in Austria where just typing your username without password would log you in. Reason? An intern committed debug code to production and nobody noticed. In my book that's not the fault of the intern but the fault of the CTO/$TECH_LEAD that hasn't implemented and religiously uphold a code re…

It is the fault of both.

Interns are not stupid and so they have to carry the burden of their mistakes too.

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#92

Post by blattimwind »

ksec wrote: post #60
mortenjorck wrote: post #54

I cannot think of any plausible way in which Apple could have influenced the date of this announcement, but the timing, given what is expected to be announced later today, is uncanny.

Imagine if Apple were to announce a Mac utilise the exact same chip. A powerful high TDP CPU will be great fit for Apple, while they continue to focus on low power and energy efficiency for their mainstream product.

The A64fx isn't that high TDP, if the reported number of ~160 W for the entire thing (including HBM) is accurate.

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#93

Post by gnufx »

sadfev wrote: post #6

Can any of the HPC experts shed some light on how these ARM chips are better than their predecessors. I toured a small cluster in LANL, where the ARM chips ran the hottest and their cooling was the loudest.

I'm not sure what predecessors that means (ThunderX2?), but these have been carefully "co-designed" for the job with experience from K Computer. Actually that's for a set of job types, which is part of the point. They also have extensive capability for low precision, if you want that. Note that it's not just at the top of top500, which is relatively uninteresting, but wins, or is up there, on things like HPCG, some sort of machine-learning benchmark, etc. K Computer also came out well generally, and persistently.

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#94

Post by jbverschoor »

ChuckNorris89 wrote: post #57
Hamuko wrote: post #43

Earlier quoted context omitted.

Just how in the world are people deploying Django apps with DEBUG = True?

Simple, human error and no code review process for your production environment. Something similar happened to a huge retailer here in Austria where just typing your username without password would log you in. Reason? An intern committed debug code to production and nobody noticed. In my book that's not the fault of the intern but the fault of the CTO/$TECH_LEAD that hasn't implemented and religiously uphold a code re…

It shouldn’t be a manual code switch in the first place.

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#95

Post by gnufx »

xhkkffbf wrote: post #8

Not to be dismissive, but can't anyone "build" the biggest supercomputer by reserving enough instances at AWS or GCP? I'm sure that AWS or GCP would like to encourage this competition, but it seems a bit, well, boring.

I haven't checked the current list, but previous ones have been roughly half "cloud provider" systems with essentially useless interconnects for real HPC work. NCSA refused to indulge in the game with Blue Waters, notably.

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#96

Post by gnufx »

sushshshsh wrote: post #41
fhqghds wrote: post #14

Earlier quoted context omitted.

yyyeah... no. A major part of what makes these machines special is their interconnect. Fujitsu is running a 6D torus interconnect with latencies well in the sub-usecond range. The special sauce is ability of cores to interact with each other with extreme bandwidth at extremely low latencies.

Thank you for this helpful info. For comparison's sake, say that you wanted to make babby's first super computer in your house with 2 laptops. That is to say, each laptop is a single core x86 system with its own motherboard and ram and ssd, and they are connected to each other in some way (ethernet? usb?) What software would one use to distribute some workload between these two nodes, what would the latency and bandw…

If you want to understand distributed-memory parallel performance you're probably better off with a simulator, like SimGrid. I don't know what bog-standard hardware you'd need to get a typical correct balance between floating point performance, memory, filesystem i/o, and general interconnect performance otherwise. No toy system is going to teach you about running a real HPC system either -- you really don't want the fastest system if it's going to fall over every few hours or basically fall apart after a year.

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#98

Post by gnufx »

floren wrote: post #47
sushshshsh wrote: post #41

Earlier quoted context omitted.

Thank you for this helpful info. For comparison's sake, say that you wanted to make babby's first super computer in your house with 2 laptops. That is to say, each laptop is a single core x86 system with its own motherboard and ram and ssd, and they are connected to each other in some way (ethernet? usb?) What software would one use to distribute some workload between these two nodes, what would the latency and bandw…

The thing to keep in mind about supercomputers is that they are designed for particular applications. Nuclear weapons simulation, biological analysis (can we run simulations and get a vaccine?), cryptanalysis. These applications are usually written in MPI, which is what coordinates communication between nodes. If you want to play with it at home, connect those laptops to an ethernet network and install MPI on them bo…

Summit and Sierra, for instance, actually run a fair range of applications fast, though Sierra is probably targetted mainly at weapons simulation-type tasks. A typical HPC system for research, e.g. university or regional, has to be pretty general purpose.

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#99

Post by ummonk »

jbverschoor wrote: post #94
ChuckNorris89 wrote: post #57

Earlier quoted context omitted.

Simple, human error and no code review process for your production environment. Something similar happened to a huge retailer here in Austria where just typing your username without password would log you in. Reason? An intern committed debug code to production and nobody noticed. In my book that's not the fault of the intern but the fault of the CTO/$TECH_LEAD that hasn't implemented and religiously uphold a code re…

It shouldn’t be a manual code switch in the first place.

What else would it be? The authentication code would live somewhere. And for debugging someone could change it to always return successful for an empty password. That debugging change shouldn't be checked in of course, and it should have been caught in code review. (It's a reasonable oversight for the authentication unit tests to only test incorrect passwords rather than the edge case of empty passwords)

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#100

Post by ummonk »

cambalache wrote: post #80
acdha wrote: post #64

Earlier quoted context omitted.

I used to support scientists. I would not expect that unless you got the documentation published in a high-profile journal.

Heheh, from the guys who use variables such as Vo ,tm,max_p, this guy expect them to RTFM.

Those are perfectly reasonable names since they're standard convention in engineering and science. It's like using i, j, and k for index variables in iterators; the meaning is clear due to convention.
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