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Parallella, a $99 Linux Supercomputer

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Re: Parallella, a $99 Linux Supercomputer

#41
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.

Small cheap cards for learning are a great idea.

But then they've included some really weird wording. They know that people are hostile to that wording, yet they chose to continue to use it.

When you're educating people it's important to be clear about terminology.

Having said that, I think it's neat, and I wish them luck. I think they're missing one of the main points of the RPi's success - it is dirt cheap. At $35 people will take a risk. At $90 people need to think about it. That might sound odd on HN where people tend to have a lot more disposable income.

Re: Parallella, a $99 Linux Supercomputer

#42

As someone who uses supercomputers, I'm not sure I entirely understand the market of this product. It's really cool and I'd love to have one to tinker with, but due to its high parallelization, I see no benefit of using this over a graphics card. I'm not sure if $99 can get you a GPU that reaches 90 GFlops though... perhaps that's where the benefit lies. EDIT: After reviewing their website, I notice they state > One…

You can't do individual branching for every single strand of computation for a typical GPU. With their chips they are trying to create a "third" category between highly parallel, but few individual instruction threads, and normal CPU's.

And the $99 is not for a mass produced card or chip, but for an initial small production run computer that includes one of the parallela chip.

You pay for a dual-core ARM computer based on the Zynq SoC (which means you get an FPGA in the deal) with an Epiphany chip. Getting a Zynq dev-board for that price in itself makes it worth it for a lot of people.

Re: Parallella, a $99 Linux Supercomputer

#44
post #30
post #20

Earlier quoted context omitted.

They do answer that on their kickstarter page: http://www.kickstarter.com/projects/adapteva/parallella-a-su... Why do you say the Parallella is a 45GHz computer? We have received a lot of negative feedback regarding this number so we want to explain the meaning and motivation. A single number can never characterize the performance of an architecture. The only thing that really matters is how many seconds and how many…

They are clearly wrong. The purpose of higher clock rates is to produce a given answer in a smaller amount of time (latency). The purpose of adding more processors (cores) is to produce more answers in a given time (throughput). They are free to report their results using any standard measurement of throughput. Their answer is weasely. But then, clock rate is irrelevant to latency and throughput. Really matters how m…

They are "clearly wrong" when talking to geeks about specific types of problems. For most most people this means nothing, and multiplying it is fine. And for a lot of situations where you are considering batch jobs, multiplying it is fine as a quick illustration. It is not as if the raw numbers tell you anything anyway, since the characteristics of the system are so unusual.

They miscalculated how people would interpret it, and got burned. But they've been clear about what it is they actually mean the whole time.

Re: Parallella, a $99 Linux Supercomputer

#45
I backed this project simply because it's a great idea to build a very small highly parallel computer that runs on very little power. Maybe this one won't hit it out of the park but it might give other people ideas. Building the first one of anything is always hard. Add a little serendipity and we might get an entirely new use for computers.

Just saying that I could do more with a $99 graphics card sort of misses the point.

Re: Parallella, a $99 Linux Supercomputer

#46
post #14
post #8

So how fast is this really? It doesn't sound like much of a supercomputer to me. If it were so super for $99, it'd have been hyped everywhere already and gamers would not buy desktops anymore. It rather sounds like a platform to practice multithreading on.

Supercomputer =/= "a fast computer".

Then what is it?

Wikipedia also seems to say it's "a fast computer": "a computer at the frontline of current processing capacity, particularly speed of calculation"

https://en.wikipedia.org/wiki/Supercomputer

Re: Parallella, a $99 Linux Supercomputer

#47
post #39
post #15

Earlier quoted context omitted.

Comparing it with a GPU is a natural discussion to have. I believe there is more information on their website to answer the question. But maybe someone else can explain the programming paradigm difference. http://www.adapteva.com/introduction/

Each of the 64 cores can independently run arbitrary C/C++ code, which is much more flexible than a GPU. Each core has 32KB of local memory, which can also be accessed by the other cores, and there's 1GB of external memory too. Specs: http://www.adapteva.com/products/silicon-devices/e64g401/ Architecture: http://www.adapteva.com/wp-content/uploads/2012/10/epiphany_... SDK docs: http://www.adapteva.com/wp-content/uplo…

I wonder how much work it would take to port cpuminer to this platform for use in mining bitcoins and litecoins. Probably not worth it for bitcoins with the new FPGA hardware but could be interesting for litecoin depending on the memory access speed to main memory.

Re: Parallella, a $99 Linux Supercomputer

#48
post #18

Can anyone explain what the practical differences between something like this and a gpgpu approach? It doesn't sound particularly performant compared to modern gpus otherwise. Maybe they add in some more general purpose instructions for a little more flexibility?

A typical GPU can execute a small number of threads on a large number of streams of data carefully laid out in memory. Every time you want to do something conditionally on just one data stream, you waste a lot of capacity.

In contrast, the Epiphany chips can execute individual threads on each core in parallel on data either local to the core (fastest), on any other core, or in separate main memory.

The current Epiphany chips aren't too spectacular, since the core count is "low". They can "only" execute 16 individual instruction streams in parallel. But that's on a chip the size of your finger nail, and their roadmap is aiming for 1024 core chips.

They're effectively aiming for people to find ways of making effective use of simple, small, power efficient cores for problems that are not "data parallel" enough to be efficiently done on GPU's.

Re: Parallella, a $99 Linux Supercomputer

#49
These guys are completely dishonest. I saw their kickstarter video where they said that for $99 you could have "a computer many times faster than anything on the market ZOMG".

Yeah, maybe it's faster for all those times during the day when you calculate matrix chain products. But for largely single-threaded tasks, like EVERYTHING you do on a day to day basis, it's going to be significantly slower than your average dual-core i3.

Re: Parallella, a $99 Linux Supercomputer

#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 obscure memory hierarchy.

The chip is plain, simple, low-power, and begging for people to have an imagination again. Stop asking what existing things you can do with it, ask what future things having something like this on a SoC would enable.

Also, you should really be thinking about the chip at the instruction level, writing toy DSL to asm compilers. Thinking along the lines of, oh yeah I'll use OpenCL so I can be hardware agnostic, is never going to allow you to see what can be possible with it. If you read the docs you'll see what a simple and regular design it is, perfect for writing your own simple tooling.

It's been a long time, but I feel like a kid again. Like when I first discovered assembly on my 8086. Finally a simple device I can tinker with, play, and wring performance out of.

Hallelujah! :)

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