Re: Re: Multicore Calculations
- To: mathgroup at smc.vnet.net
- Subject: [mg60862] Re: [mg60809] Re: [mg60769] Multicore Calculations
- From: Manuel Schmidt <Manuel.Schmidt at physik.uni-wuerzburg.de>
- Date: Fri, 30 Sep 2005 06:38:00 -0400 (EDT)
- References: <200509280541.BAA08344@smc.vnet.net> <200509290941.FAA01101@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
this are the informations about my system:
Dual Opteron
2G RAM
SuSE Prof. 9.3
Mathematica 5.2
The threads do not show up independently on this system (it is a
cip-pool). On my local computer, I have only one processor (Athlon64)
with Gentoo (I know, it is not supported) running and there the kernel
uses 4 processes. Can one set from outside (as user or installer) how
many Threads a kernel uses?
Thanks,
Manuel
On Thu, 2005-09-29 at 05:41 -0400, Jeff Bryant wrote:
> The results you get depend on a couple of factors. I'll provide a
> couple comments and perhaps other, more qualified people can respond
> directly if necessary for additional details.
>
> What platform (CPU and OS) are you running on? That will determine if
> a) we support multiple processors/cores
> and
> b) if top shows threads independently of their parent process.
>
> Also, vector-vector (BLAS level 1) and matrix-vector operations (BLAS
> level 2) don't parallelize terribly well, so there will be little
> benefit to multiple processors for those types of operations, anyway.
>
> -Jeff
>
> Manuel Schmidt wrote:
>
> > Hi all,
> >
> > i'm wondering, how one can convince the MathKernel to do a numerical
> > linear algebra calculation on two processors at the same time in 5.2.
> >
> > Am I right, that this should be computed on two processors (if
> > available):
> >
> > vec1 = Table[Random[], {i, 5000000}];
> > vec2 = Table[Random[], {i, 5000000}];
> >
> > While[True,Dot[vec1, vec2]]
> >
> > or a big matrix and a vector
> >
> > matrix.vector;
> >
> > Anyways, I see in top only one kernel running. There is only one thread.
> > Are there different binaries for the multicore and the singlecore
> > version?
> >
> > Thanks,
> >
> > Manuel
> >
> >
- References:
- Multicore Calculations
- From: Manuel Schmidt <Manuel.Schmidt@physik.uni-wuerzburg.de>
- Re: Multicore Calculations
- From: Jeff Bryant <jeffb@wolfram.com>
- Multicore Calculations