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using two Pis as one dual-core?

Posted: Mon Oct 22, 2012 12:15 am
by tenebrescence
Is it possible to use two Raspberry Pi computers together in such a way that the result is effectively one dual-core computer? If so, how would one go about implementing this?

My apologies if I don't use proper terminology, if I'm being unclear, if there's already a thread regarding this (I couldn't find it), or if I'm posing it in the wrong place. And please let me know if I'm doing any of those so I can correct it.

Re: using two Pis as one dual-core?

Posted: Mon Oct 22, 2012 3:00 am
by billb
No, not really...

You can create what they're calling a >>>Bramble<<< -- a cluster of Raspberry Pis -- but it's not the same as having a multi-core CPU.

Here's one made from 64 Pis:

http://www.southampton.ac.uk/mediacentr ... uter.shtml

Re: using two Pis as one dual-core?

Posted: Mon Oct 22, 2012 5:35 pm
by tenebrescence
Ah well.. Thank you for replying! And I'm checking out the Bramble now.

Re: using two Pis as one dual-core?

Posted: Tue Oct 23, 2012 5:12 am
by saintdev
Commonly referred to as a Beowulf cluster.

Re: using two Pis as one dual-core?

Posted: Tue Oct 23, 2012 8:13 am
by jaromanda
a "cluster" of 2 Rpi would be called a circumference, surely

Re: using two Pis as one dual-core?

Posted: Tue Oct 23, 2012 5:56 pm
by tenebrescence
It turns out that a "cluster" (even of two; and I rather like the term "circumference" for 2 RPis!) is actually what I want to do. I want to learn how parallel computing works (clearly I have a long way to go) and be able to write code that I can actually test.

Re: using two Pis as one dual-core?

Posted: Wed Oct 31, 2012 8:17 pm
by ech0
What exactly is a bramble/cluster of raspberry pis?
I understand it's parallel computing but how would you explain it in a simple manor?
If I were to connect my two pis, would I essentially have a 'faster' PI connected to 1 monitor?
Ex. double RAM/CPU?

Re: using two Pis as one dual-core?

Posted: Wed Oct 31, 2012 9:08 pm
by rickseiden
jaromanda wrote:a "cluster" of 2 Rpi would be called a circumference, surely
That was really, really bad. So bad, that it was good! Well played.

Re: using two Pis as one dual-core?

Posted: Wed Oct 31, 2012 9:20 pm
by billb
ech0 wrote:If I were to connect my two pis, would I essentially have a 'faster' PI connected to 1 monitor?
No, it would not be for general use. But two or more Pis would have the potential to perform certain tasks faster than a single Pi IF the task lent itself well to parallel computing AND software was written for that task.

From what I've read, a cluster of Pis or "Bramble" (or Beowulf cluster, whatever you call it) might be OK as an educational tool for learning more about parallel computing, but there are better solutions in terms of price to performance.

Re: using two Pis as one dual-core?

Posted: Wed Oct 31, 2012 10:37 pm
by ghans
i.e. no existing consumer software will ever work faster on two Pis compared to one.
Nor any Linux GUI apps.

ghans

Re: using two Pis as one dual-core?

Posted: Fri Nov 02, 2012 3:10 pm
by ZirconiumX
tenebrescence wrote:Is it possible to use two Raspberry Pi computers together in such a way that the result is effectively one dual-core computer? If so, how would one go about implementing this?

My apologies if I don't use proper terminology, if I'm being unclear, if there's already a thread regarding this (I couldn't find it), or if I'm posing it in the wrong place. And please let me know if I'm doing any of those so I can correct it.
Kind of: SSI allows you to fool Linux into thinking that there is one dual-core Pi.

I'd be willing to attempt a R-Pi distro using SSI, if you're interested and willing to help.

Matthew:out

Re: using two Pis as one dual-core?

Posted: Sun Nov 11, 2012 11:27 pm
by munklefish
ZirconiumX wrote:
tenebrescence wrote:Is it possible to use two Raspberry Pi computers together in such a way that the result is effectively one dual-core computer? If so, how would one go about implementing this?

My apologies if I don't use proper terminology, if I'm being unclear, if there's already a thread regarding this (I couldn't find it), or if I'm posing it in the wrong place. And please let me know if I'm doing any of those so I can correct it.
Kind of: SSI allows you to fool Linux into thinking that there is one dual-core Pi.

I'd be willing to attempt a R-Pi distro using SSI, if you're interested and willing to help.

Matthew:out
Thats sounds good to me!!!

Re: using two Pis as one dual-core?

Posted: Mon Nov 12, 2012 12:51 am
by dextrus
You already have a dual-core device. Your GPU runs in parallel with your CPU (Arm). It does depend on what you want to do, but you can get your GPU to do more than just graphics.

/Dextrus