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 joules YOUR application consumes on a specific platform.
Still, we think multiplying the core frequency(700MHz) times the number of cores (64) is as good a metric as any. As a comparison point, the theoretical peak GFLOPS number often quoted for GPUs is really only reachable if you have an application with significant data parallelism and limited branching. Other numbers used in the past by processors include: peak GFLOPS, MIPS, Dhrystone scores, CoreMark scores, SPEC scores, Linpack scores, etc. Taken by themselves, datasheet specs mean very little. We have published all of our data and manuals and we hope it's clear what our architecture can do. If not, let us know how we can convince you.
Why do you say the Parallella is a 45GHz computer?
This is a Kickstarter project. In order to be successful, we need to attract as much attention from spam blogs as possible. To do that, facts are not particularly useful. What we need is something exciting. If we say we have 64 cores, that's not exciting. 64? I've forgotten how to count that low. Similarly, if we say we have a 700MHz processor, most people listening to us talk will actually start laughing in our faces. So that's no good. But thanks to our mathematical forefathers, there are many ways to make small numbers big. We could add the two numbers, saying we have a 764MHz machine. But that's not exciting, and the units don't work. We could divide the two numbers, yielding 10.94MHz. The units work, but that number is even smaller! Finally, we could try multiplication! And, boy, does that deliver! 45GHz!
TLDR: The only reason you're here is because of our misleading and dishonest claim. But now you're here. Please cough up your hard-earned cash which we might not use to go on a nice tropical vacation. You can trust us, we'd never mislead you...
Their answer to 'Why do you call the Parallella a supercomputer?' is also pretty curious: ;)
> The Parallella project is not a board, it's intended to be a long term computing project and community dedicated to advancing parallel computing.
> The current $99 board aren't considered supercomputers by 2012 standards, but a cluster of 10 Parallella boards would have been considered a supercomputer 10 years ago.
Wait, what? :D (emphasis mine)
> Our goal is to put a bona-fida supercomputer in the hands of everyone as soon as possible but the first Parallella board is just the first step. Once we have a strong community in place, work will being on PCIe boards containing multiple 1024-core chips with 2048 GFLOPS of double precision performance per chip. At that point, there should be no question that the Parallella would qualify as a true supercomputing platform.
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 much more work per cycle you get done, how fast you can move IO, and the cost of throughput per watt (and whether the system can meet your requirements at all).
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.
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 joules YOUR application consumes on a specific platform.
Still, we think multiplying the core frequency(700MHz) times the number of cores (64) is as good a metric as any. As a comparison point, the theoretical peak GFLOPS number often quoted for GPUs is really only reachable if you have an application with significant data parallelism and limited branching. Other numbers used in the past by processors include: peak GFLOPS, MIPS, Dhrystone scores, CoreMark scores, SPEC scores, Linpack scores, etc. Taken by themselves, datasheet specs mean very little. We have published all of our data and manuals and we hope it's clear what our architecture can do. If not, let us know how we can convince you.