Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

El Capitan: New supercomputer is the fastest

spectrum.ieee.org

Post reply on HN
Print view View original

11–20 of 106 posts

Re: El Capitan: New supercomputer is the fastest

#11

Post by TeMPOraL »

olao99 wrote: 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"

Pot, meet kettle? It's usually the industry that's leading with "write inefficient code, hardware is cheaper than dev time" approach. If anything, I'd expect a long-running physics research project to have well-optimized code. After all, that's where all the optimized math routines come from.

Re: El Capitan: New supercomputer is the fastest

#13

Post by bongodongobob »

olao99 wrote: 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"

My brother in Christ, it's a supercomputer. What an odd question.

Re: El Capitan: New supercomputer is the fastest

#14

Post by CapitalistCartr »

olao99 wrote: 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.

Re: El Capitan: New supercomputer is the fastest

#15

Post by p_l »

olao99 wrote: 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 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 rest of the stockpile) or how exact the data is.

And remember that there is more than one user of every supercomputer deployed at such labs, whether it be multiple "paying" jobs like research simulations, smaller jobs run to educate, test, and optimize before running full scale work, etc.

AFAIK for considerable amount of time, supercomputers run more than one job at a time, too.

Re: El Capitan: New supercomputer is the fastest

#16

Post by JumpCrisscross »

olao99 wrote: 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"

> Are they trying to model every single atom?

Given all nuclear physics happens inside atoms, I'd hope they're being more precise.

Note that a frontier of fusion physics is characterising plasma flows. So even at the atom-by-atom level, we're nowhere close to a solved problem.

Re: El Capitan: New supercomputer is the fastest

#17

Post by shagie »

einpoklum wrote: post #4

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 would reference an older article on super computers and the nuclear weapon arsenal.

https://www.techtarget.com/searchdatacenter/news/252468294/C...

> "The Russians are fielding brand new nuclear weapons and bombs," said Lisa Gordon-Hagerty, undersecretary for nuclear security at the DOE. She said "a very large portion of their military is focused on their nuclear weapons complex."

> It's the same for China, which is building new nuclear weapons, Gordon-Hagerty said, "as opposed to the United States, where we are not fielding or designing new nuclear weapons. We are actually extending the life of our current nuclear weapons systems." She made the remarks yesterday in a webcast press conference.

> ...

> Businesses use 3D simulation to design and test new products in high performance computing. That is not a unique capability. But nuclear weapon development, particularly when it involves maintaining older weapons, is extraordinarily complex, Goldstein said.

> The DOE is redesigning both the warhead and nuclear delivery system, which requires researchers to simulate the interaction between the physics of the nuclear system and the engineering features of the delivery system, Goldstein said. He characterized the interaction as a new kind of problem for researchers and said 2D development doesn't go far enough. "We simply can't rely on two-dimensional simulations -- 3D is required," he said.

> Nuclear weapons require investigation of physics and chemistry problems in a multidimensional space, Goldstein said. The work is a very complex statistical problem, and Cray's El Capitan system, which can couple this computation with machine learning, is ideally suited for it, he said.

---

This isn't designing new ones. Or blowing things up ( https://www.reuters.com/article/us-usa-china-nuclear/china-m... ) to see if they still work. It is simulating them to have the confidence that they still work - and that the adversaries of the US know that the scientists are confident that they still work without having to blow things up.

Re: El Capitan: New supercomputer is the fastest

#18

Post by alephnerd »

comboy wrote: post #6
einpoklum wrote: post #4

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 guess it's unlikely to be the real use case. The real one is classified. Plus it's not like more deadly nuclear weapons would change anything, we can do bad enough with what we already have.

> I'd guess it's unlikely to be the real use case

I can safely say that nuclear simulations are one of the major drivers for HPC research globally.

It is not the only one (genomics, simulations, fundamental research are also major drivers) but it is a fairly prominent one.

Re: El Capitan: New supercomputer is the fastest

#19

Post by alephnerd »

olao99 wrote: 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"

> I fail to understand how these nuclear bomb simulations require so much compute power

I wrote a previous HN comment explaining this:

Tl;dr - Monte Carlo Simulations are hard and the NPT prevents live testing similar to Bikini Atoll or Semipalatinsk-21

https://news.ycombinator.com/item?id=39515697

Re: El Capitan: New supercomputer is the fastest

#20

Post by postalrat »

rbanffy wrote: post #10
einpoklum wrote: post #4

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…

The whole point of testing (and making) deadly nuclear weapons is to ensure they are never used again. The Mutually Assured Destruction doctrine has kept us alive through the darkest pf the Cold War (also keeping the Cold War cold). In order to credibly threaten anyone who tries to annihilate you with certain annihilation is with lots of such doomsday weapons. We have lived in this Mexican standoff for longer than we…

Are are living in the darkest days of the cold war right now.
Post reply on HN