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

Japan Captures TOP500 Crown with Arm-Powered Supercomputer

top500.org

Post reply on HN
Print view View original

31–40 of 220 posts

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#32

Post by leeter »

fhqghds wrote: post #7
ViralBShah wrote: post #3

Given that today's HPC architectures are mostly power constrained, and a majority of the FLOPS often come from GPUs (for their flop/watt ratios), this direction is not surprising. ARM has been making major strides in the high performance area. The new AWS Graviton processors are pretty nice from what I have heard. And then there's the ARM in Mac. Yup and Julia will run on all of these! While I say all of this, I shou…

Get ready for a surprise then: all those FLOPS are coming from the ARM cores.... This beast has no GPUs: https://postk-web.r-ccs.riken.jp/spec.html

So looking at anandtech's breakdown the CPUs are closer to a knights landing 'CPU/GPU' than a traditional CPU (currently). They also have a ton of HBM2 right next to the dies so this should be insanely fast as they can feed those cores very very quickly regardless of how fast each core is by clock and pipeline. That should massively reduce stalls.

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#33

Post by rrss »

lukevp wrote: post #19
blopeur wrote: post #11

Earlier quoted context omitted.

A64fx have on board HMB -> that means no dram. If you look at the fugaku mother board their is no Dimm slots. All the memory is on the same package as the CPU. This delivers a huge boost in bandwith. HMB stand for high memory bandwidth. It offers up to 900 GB/s. Now if you add the tofu interconnect on top you have a systems finely tuned for maximising data movement. Remember : compute is cheap, communication is expen…

That's fascinating. I know that AMD has been touting HBM as a faster memory subsystem for their GPUs, is that the same as HMB where it's stacked? Or are they just calling it something similar?

It's the same thing. High end GPUs have been using HBM2 for a few years, A64fx uses HBM2 for CPU memory.

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#34

Post by stephencanon »

leeter wrote: post #32
fhqghds wrote: post #7

Earlier quoted context omitted.

Get ready for a surprise then: all those FLOPS are coming from the ARM cores.... This beast has no GPUs: https://postk-web.r-ccs.riken.jp/spec.html

So looking at anandtech's breakdown the CPUs are closer to a knights landing 'CPU/GPU' than a traditional CPU (currently). They also have a ton of HBM2 right next to the dies so this should be insanely fast as they can feed those cores very very quickly regardless of how fast each core is by clock and pipeline. That should massively reduce stalls.

The "traditional CPU" portion of the core is a bit more capable than KNL, but yeah, that's roughly accurate.

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#37

Post by vangelis »

3pt14159 wrote: post #24
jbay808 wrote: post #21

Earlier quoted context omitted.

To be fair, I wouldn't host my website on my world-class supercomputer either, if I had one...

To be even fairer, I've served a shit ton of traffic on a small DigitalOcean droplet and never had issues because my stack is reasonable.

Is there a CDN sitting between your small droplet and the world?

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#39

Post by sushshshsh »

floren wrote: post #16
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.

The ranking is calculated based on the Linpack benchmark. Being a parallel application, performance is not simply scaled to number of processors; the network interconnect is hugely important. Now, although Linpack is a better evaluation metric for a supercomputer than simply totaling up # of processors and RAM size, it's still a very specific benchmark of questionable real-world utility; people like it because it giv…

I am curious to learn a bit more about how supercomputer scores measure proportionally to "real world performance", which is a hard thing to quantify since there are probably hundreds of different application "types" in the "real world".

Combine this with the fact that many applications are limited by network throughput rather than by CPU/SSD/RAM/PCIE, and performance becomes a hard thing to quantify even in terms of "how many ARM cores do i need to buy to make my CPU not be the bottleneck"

There are benchmarks for ARM linux compilation and ARM openjdk performance benchmarks which are a good start, but I don't know how to compare SKUs between those ARMs and the ones found in top500 supercomputers.

Re: Japan Captures TOP500 Crown with Arm-Powered Supercomputer

#40

Post by lorenzhs »

davidhyde wrote: post #12

The site of the organisation responsible for assessing the fastest computers in the world succumbs to the hacker news hug of death.

Oh my, it's a django app with debug mode enabled. I just got an InterfaceError with the full traceback and django configuration. (I've emailed them so they can fix it)
Post reply on HN