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El Capitan: New supercomputer is the fastest

spectrum.ieee.org

31–40 of 106 posts

Re: El Capitan: New supercomputer is the fastest

#31
post #23

Noting here that 2700 quadrillion operations per second is less than the estimated sustained throughput of productive bfloat16 compute during the training of the large llama3 models, which IIRC was about 45% of 16,000 quadrillion operations per second, ie 16k H100 in parallel at about 0.45 MFU. The compute power of national labs has fallen far behind industry in recent years.

Training an LLM (basically Transformers) is different workflow from Nuclear Simulations (basically Monte Carlo simulations) There are a lot of intricates, but at a high level they require different compute approaches.

Absolutely. Though the performance of El Capitain is only measured by a linpack benchmark not the actual application.

Re: El Capitan: New supercomputer is the fastest

#32
Do super computers need proximity to other compute nodes in order to perform this kind of computations?

I wonder what would happen if Apple offered people something like iCloud+ in exchange for using their idle M4 compute at night time for a distributed super computer.

Re: El Capitan: New supercomputer is the fastest

#33

This is great but I absolutely love that poster of el capitan on the supercomputer racks ! Also TIL there is a list of top500 at https://www.top500.org/lists/top500/2024/11/

That's a pretty standard Cray feature for systems larger than a few cabinets. El Capitan has the landscape, Hopper at NERSC had a photo of Grace Hopper, Aurora at ANL has a creamy gradient reminiscent of the Borealis, and on and on. Gives them a bit of character beyond the bad-ass Cray label on the doors.

Re: El Capitan: New supercomputer is the fastest

#34

Do super computers need proximity to other compute nodes in order to perform this kind of computations? I wonder what would happen if Apple offered people something like iCloud+ in exchange for using their idle M4 compute at night time for a distributed super computer.

If you weren’t aware - https://en.m.wikipedia.org/wiki/Folding@home

Re: El Capitan: New supercomputer is the fastest

#35

So, they built this supercomputer to test new and more deadly nuclear weapons. That makes me so "happy". I am absolutely not worried about two nuclear powers being close to the brink of direct war, even as we speak; nor about the abandonment of the course of nuclear disarmament treaty; nor about the repeated talk of a coming war against certain Asian powers. Everything is great and I'll just fawn over the colorful li…

Eh, we have all the nukes we need and we already know how to build them. This is going to help more with fusion power than fusion explosives.

Re: El Capitan: New supercomputer is the fastest

#36

Do super computers need proximity to other compute nodes in order to perform this kind of computations? I wonder what would happen if Apple offered people something like iCloud+ in exchange for using their idle M4 compute at night time for a distributed super computer.

If you weren’t aware - https://en.m.wikipedia.org/wiki/Folding@home

More of a SETI@home man myself.

Re: El Capitan: New supercomputer is the fastest

#37

Do super computers need proximity to other compute nodes in order to perform this kind of computations? I wonder what would happen if Apple offered people something like iCloud+ in exchange for using their idle M4 compute at night time for a distributed super computer.

The thing that sets these machines apart from something that you could set up in AWS (to some degree), or in a distributed sense like you're suggesting is the interconnect, how the compute nodes communicate. For a large system like El Capitan, you're paying a large chunk of the cost in connecting the nodes together, low latency, interesting topologies that ethernet, nor even Infiniband can get close to. Code that requires a lot of DMA or message passing really will take up all of the bandwidth that's available, that becomes the primary bottleneck in these systems.

The interconnect has been Cray's bread and butter for multiple decades: Slingshot, Dragonfly, Aries, Gemini, SeaStar, numalink via sgi, etc. and those for the less massively parallel systems before those.

Re: El Capitan: New supercomputer is the fastest

#38
post #27
post #15

Earlier quoted context omitted.

It literally requires simulating each subatomic particle, individually. The increases of compute power have been used for twin goals of reducing simulation time (letting you run more simulations) and to increase the size and resolution. The alternative is to literally build and detonate a bomb to get empirical data on given design, which might have problems with replicability (important when applying the results to r…

Are they always designing new nuclear bombs? Why the ongoing work to simulate?

The euphemistic term used in the field is "stockpile stewardship", which is a catch-all term involving a wide range of activities, some of them forward-looking.

Re: El Capitan: New supercomputer is the fastest

#39
post #7

I fail to understand how these nuclear bomb simulations require so much compute power. Are they trying to model every single atom? Is this a case where the physicists in charge get away with programming the most inefficient models possible and then the administration simply replies "oh I guess we'll need a bigger supercomputer"

It's because of the way the weapons are designed, which requires a CNWDI clearance to know, so your curiosity is not likely to be sated.

> It's because of the way the weapons are designed, which requires a CNWDI clearance to know, so your curiosity is not likely to be sated.

While that's true, the information that is online is surprisingly detailed.

For example, this series "Nuclear 101: How Nuclear Bombs Work"

https://www.youtube.com/watch?v=zVhQOhxb1Mc

https://www.youtube.com/watch?v=MnW7DxsJth0

Re: El Capitan: New supercomputer is the fastest

#40

So, they built this supercomputer to test new and more deadly nuclear weapons. That makes me so "happy". I am absolutely not worried about two nuclear powers being close to the brink of direct war, even as we speak; nor about the abandonment of the course of nuclear disarmament treaty; nor about the repeated talk of a coming war against certain Asian powers. Everything is great and I'll just fawn over the colorful li…

I'd rather have a few supercomputers doing stockpile stewardship over being tested live. As much as I hate it personally, these weapons are a part of our society for better or for worse until we (as in the people) decide they won't be by electing those that will help dismantle the programs. They should be maintained and these tools help in that.
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