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Parallella, a $99 Linux Supercomputer

zdnet.com

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Re: Parallella, a $99 Linux Supercomputer

#141

Post by backprojection »

qb45 wrote: post #126
backprojection wrote: post #122

How does this compare the the new Intel MIC (Xeon Phi) co-processor boards? I think they claim 1TFLOP. Can we think of this as a low-powered alternative? http://en.wikipedia.org/wiki/Intel_MIC

The general idea is similar - lots of cores with distributed SRAM memory and some shared DRAM, all sitting on 2D mesh network. The main difference is that Epiphany is made of custom simple RISC cores, while Xeon Phi uses 1st gen Pentiums with huge SIMD FPUs slapped on for higher FP throughput (and TDP).

Interesting.

It looks like (from info on wikipedia pages) the Xeon Phi 3100, gets about 3.3 GFLOPS/WATT, whereas the Epiphany E64G401 manages about 50 GFLOPS/WATT.

So something like 10 of these might compare to 1 xeon phi, and still be cheaper in terms of hardware, and much cheaper in terms of power consumption.

Re: Parallella, a $99 Linux Supercomputer

#142

Post by jholman »

1amzave wrote: post #140
jholman wrote: post #123

Earlier quoted context omitted.

First of all, which is the NP-hard pathfinding problem you're talking about? When I hear "pathfinding" I think "shortest path", which is (deterministic) polynomial time (exact class dependant on exactly which variant of the problem, but even Floyd-Warshall is Θ(|V|³)). --- Anyway, no. If you have an NP-hard problem, and you want an exact answer (i.e. you are denying yourself approximate solutions), and you want to so…

> Parallel processing models give you, at best, linear speedup. Most commonly, yes, though in practice superlinear speedups can occur in some situations. (Not that this negates your overall point, just a nitpick.)

Can you give one or more examples?

Re: Parallella, a $99 Linux Supercomputer

#143

Post by lgeek »

qb45 wrote: post #126
backprojection wrote: post #122

How does this compare the the new Intel MIC (Xeon Phi) co-processor boards? I think they claim 1TFLOP. Can we think of this as a low-powered alternative? http://en.wikipedia.org/wiki/Intel_MIC

The general idea is similar - lots of cores with distributed SRAM memory and some shared DRAM, all sitting on 2D mesh network. The main difference is that Epiphany is made of custom simple RISC cores, while Xeon Phi uses 1st gen Pentiums with huge SIMD FPUs slapped on for higher FP throughput (and TDP).

Off the top of my mind (sorry, I don't have the time to double check now):

Phi has shared GDDR and distributed caches. Phi cores and caches are connected through a bidirectional ring interconnect, not a 2D mesh network. Still similar, but not as much.

Re: Parallella, a $99 Linux Supercomputer

#144

Post by m_mueller »

rayiner wrote: post #57
swalsh wrote: post #34

There's so much negativity in this thread, wasn't the whole idea that these guys had plans and an architecture to scale up to the order of a terra-flop by 2014, and 20 by 2022? And look! they're shipping. This first chip may not be impressive, but I'll welcome a new player to the market who has big plans to innovate.

I don't get the negativity either. If you look at the architecture manual, this is like a cheap Tilera. It's an interesting programming model (lots of cores in a shared memory SMP with weak memory ordering), and the CPU's are pretty vanilla RISC architectures. For $99, it's a great way to play with something that has the properties of the kinds of CPU's you might see in a future supercomputer.

Not to take away anything from Parallela, but you can also get to play around with something that's used in today's supercomputers by buying any Geforce 5xx and start programming in CUDA.

A fully documented ARM architecture as an accelerator chip is certainly interesting though. It will take time until the software tooling catches up, but the initial buzz in the HPC community about those ARM newcomers is certainly there. I'd give them a good chance in the long run to outrun Intel MICs and catch up to NVIDIA Tesla.

What I'd like to see next is a PCI express expansion card using this technology. See, one of the great benefits about Tesla cards is that you can swap them out in your supercomputers just like you do it with RAM - and you get the newest chip architecture, as long as your PCI bus can handle the load. For multi purpose systems you often still like to have a good number of x86 cores in there however.

Re: Parallella, a $99 Linux Supercomputer

#145

Post by m_mueller »

mrb wrote: post #119

"this board should deliver about 90 GFLOPS of performance, or --in terms PC users understand-- about the same horse-power as a 45GHz CPU." This is wrong. A 4-core 3.0 GHz x86-64 processor delivers more GFLOPS than the Parallela: 96 GFLOPS with SSE instructions, because each core can execute 8 single precision instructions, 4 adds and 4 muls, each cycle. And yes, when Parallela claims 90 GFLOPS, they mean single-preci…

Exactly right. ARMs lure isn't really the current performance for supercomputing, it's rather the expectation that they will hit the next big performance wall much later than x86 because of its simple architecture that's suitable for the maximum amount of cores per die space. Give it 2-3 years and we might have the big step in supercomputing architecture at hand.

Re: Parallella, a $99 Linux Supercomputer

#146

Post by lgeek »

NewAccnt wrote: post #107

I wonder how those in the performance computing sector feel about running a proprietary supervisor with built in DRM on each and every CPU? Raspberry users might not care when for just hobbyist applications, but I doubt any serious scientist is going to overlook that. http://www.arm.com/products/processors/technologies/trustzon...

Trustzone is just a set of hardware features. Most ARM devices don't come with a proprietary supervisor. In fact, Linux used to run in the secure world on some development devices.

Re: Parallella, a $99 Linux Supercomputer

#147

Post by marshray »

mrb wrote: post #131
rys wrote: post #26

Earlier quoted context omitted.

You can get close to 1TF in the GPU space for $99 these days, but at much lower power efficiency. The Adapteva hardware looks to be around 18GF/W, whereas a GPU is about half that at $99.

The AMD Radeon HD 7790 ($150) does 21 GFLOPS/Watt. So I would say Adapteva is definitely comparable to GPUs in this approximate price range.

And that's just at the Kickstarter price. GPUs have had decades of competition to squeeze the extra costs out and build up economies of scale.

Re: Parallella, a $99 Linux Supercomputer

#148

Post by marshray »

mtrimpe wrote: post #4
rys wrote: post #2

I find it incredibly dishonest of Adapteva to equate it to a "theoretical 45 GHz CPU". There are much better ways to talk about the performance level of their hardware than that metric, especially given the rest of the text in their Kickstarter pitch is aimed at people who need to inherently understand the hardware's execution model in order to program it effectively. The computing industry has established language a…

This board should deliver about 90 GFLOPS of performance, or — in terms PC users understand — about the same horse-power as a 45GHz CPU. That doesn't seem too outrageous to me. Edit: They state the real fact and then give another figure explicitly stating it's an attempt to translate this into a metric the average user can somewhat relate to. According to http://en.wikipedia.org/wiki/FLOPS#Computing it seems that the…

Because all of us dumb PC users measure performance in terms of "horse-power". :-)

Re: Parallella, a $99 Linux Supercomputer

#149

Post by nashequilibrium »

phaet0n wrote: post #50

I'm really disappointed about how shallow the discussions about Adapteva are, and have been, on HN. To remind everyone, the H = hacker. This device is a godsend, as far as I'm concerned. For the first time ever I get fully documented access to compute array on chip. No the architecture wasn't designed for anything specific, like graphics, but that means I don't get bogged down in details I don't care about, like some…

"I'm really disappointed about how shallow the discussions about Adapteva are, and have been, on HN. To remind everyone, the H = hacker."

Thank You for saying this, i wanted to write about this but never found the time. I have started reading HN less and less because there is no longer substance in the comments and they usually focus on something that makes up 10% of the article, i actually find it weird at times. I am depending more and more on the weekly newsletters but still miss the old comments which were optimistic, on point and taught me something about the subject central to the article.

Back on topic. "What Adapteva has done is create a credit-card sized parallel-processing board" This is so cool,as a linux user I hope to get my hands on one of these asap! Take a look at the kickstarter video http://www.kickstarter.com/projects/adapteva/parallella-a-su...

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