comp.lang.idl-pvwave archive: archive » Re: IDL Matrix Multiply and Dual-Core CPUs

Home » Public Forums » archive » Re: IDL Matrix Multiply and Dual-Core CPUs

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: IDL Matrix Multiply and Dual-Core CPUs [message #60250 is a reply to message #60249]

Fri, 09 May 2008 11:28

s.haenger
Messages: 4
Registered: May 2008

Junior Member

On 9 Mai, 20:20, FÖLDY Lajos <fo...@rmki.kfki.hu> wrote:
> oops, I have written IDL 7 time to the ATLAS test. Corrected below.
>
> lajos
>
> I have run some tests on a quad-core Intel Core2 Q6600 / linux 64 bit
> machine.
>
> On Fri, 9 May 2008, s.haen...@gmail.com wrote:
>
> Hi,
>
> I have a Problem with IDL 7.0
> We have to multiply large matrices. With some matrix sizes, the CPU
> usage is 100% but for most of the matrices it is 50%. (I'm runnning it
> on a Intel T7250 (Dual Core, 2GHz, 2MB L2 Cache))
>
> The CPU System Variable is configured like this:
> IDL> print, !CPU
> { 0 0 2 2
> 100000 0}
>
> Now we do this:
> matA = randomn(42, 2000, 2200)
> matB = randomn(43, 2020, 2000)
> matIdl = matA##matB
>
> So now i've got a CPU usage of 100%
>
> # of threads IDL 7 time
> 1 12.476210
> 2 6.5931890
> 3 5.2085290
> 4 4.9191489
>
> it scales well for two cores, so the CPU usage should be near 100% for two
> threads.
>
> but with this:
> matA = randomn(42, 2500, 2500)
> matB = randomn(43, 2520, 2500)
> matIdl = matA##matB
>
> the cpu usage is around 50%-60%
>
> # of threads IDL 7 time
> 1 22.034877
> 2 11.681226
> 3 9.7771089
> 4 9.3093379
>
> again, CPU usage should be near 100% for two cores.
>
> Just for comparison, ATLAS (http://math-atlas.sf.net) times:
>
> # of threads ATLAS time
> 1 4.4285851
> 4 1.1784132
>
> and
>
> # of threads ATLAS time
> 1 7.8148808
> 4 2.1345751
>
> regards,
> lajos
>
>

Sorry, I forgot to mention... I'm running Windows XP 32bit with 2GB of
Ram
I also tested it on a second machine with a 3GHz Dual Core and it
showed the same cpu usages...

regards,
Samueö

Report message to a moderator

[Message index]

		Re: IDL Matrix Multiply and Dual-Core CPUs By: Pierre V. on Fri, 09 May 2008 11:34
		Re: IDL Matrix Multiply and Dual-Core CPUs By: s.haenger on Fri, 09 May 2008 11:28
		Re: IDL Matrix Multiply and Dual-Core CPUs By: Foldy Lajos on Fri, 09 May 2008 11:20
		Re: IDL Matrix Multiply and Dual-Core CPUs By: Foldy Lajos on Fri, 09 May 2008 11:16
		Re: IDL Matrix Multiply and Dual-Core CPUs By: Bringfried Stecklum on Fri, 09 May 2008 09:09
		Re: IDL Matrix Multiply and Dual-Core CPUs By: s.haenger on Tue, 20 May 2008 00:21
		Re: IDL Matrix Multiply and Dual-Core CPUs By: Karl[1] on Tue, 20 May 2008 11:19
		Re: IDL Matrix Multiply and Dual-Core CPUs By: s.haenger on Thu, 17 July 2008 01:42

Previous Topic:	Re: appending to column
Next Topic:	a question about IDLgrSurface

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Sat Oct 11 09:03:46 PDT 2025

Total time taken to generate the page: 1.91997 seconds