BLAS on a Quad-Core ARM SoC

ARM support has been added into the mainline ATLAS distribution. The current stable version 3.10.0 supports ARM. Benchmarks for multicore ARM processor (1GHz Dual-Core - PandaBoard) are online at http://www.vesperix.com/arm/atlas-arm/bench/gcc-a9-3.10.0-nonieee/index.html . In short for Matrix Size 2000 x 2000

MFLOPs for SGEMM using one core = 1500

MFLOPs for DGEMM using one core = 757

MFLOPs for SGEMM using two cores = 3000
MFLOPs for DGEMM using two cores = 1426



MFLOPs for SGETRF using one core = 1347
MFLOPs for DGEMM using one core = 700


MFLOPs for SGETRF using two cores = 2312
MFLOPs for DGEMM using two cores = 1224

The speedup is close to linear for two processors. I am keen to see how it trends when more number of cores are introduced. How will the cache behave (especially for sparse matrix operations where the access to the memory is normally irregular) ?

ODROID-X - Quad-Core ARM Cortex A9 - 1GB RAM - 32/32 L1 and 1MB L2 cache - I am running Linux Linaro - Kernel 3.6.2

Currently in the market the maximum count for cores on an ARM processor is 4. Samsung Exynos4412 is one such where each core runs at 1.4 GHz. Exynos4412 is coming with ODROID-X which is a $129 single-board computer with 1GB RAM. ODROID-X seems the best candidate for doing some multicore HPC.

I might be celebrating my EID with BLAS and ARM :P

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Jargon Alert !!

BLAS: Basic Linear Algebra Subprograms.

MFLOPs: Millions of Floating Point Operations per Second.

S: Single Precision.

D: Double Precision.

GE: General Matrix.

MM: Matrix Multiply - a subroutine in BLAS.

TR: Tridiagonal.

some links worth visiting

http://www.galaxys3blog.net/2012/05/exynos-4412-cortex-a9-15ghz.html

http://www.vesperix.com

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On Truth

Dear X,

You asked me do I write. Yes I do. I used to write and was productive before love stroke me. I am getting over it and becoming normal again. This evening I put some of my notes out from a dusty self and started collecting them again.

I am writing to you about "Truth" - The Manifest Truth and How to grasp it.

The manifest truth is out the there naked. We are the ones who tend not to look at it. The truth is in the book of nature, we just have to spell it out [Sir Karl Popper].

Dear X, one way is the Baconian way, that is to purge our mind of all anticipation or conjectures or guesses or prejudice. Socrates way is to find counter instances of the things. These counter instances will help in destroying the prejudices we have - through tradition, false belief. Such that instead of justifying our beliefs of truth, about our knowledge, i.e. instead of looking at what is true about our beliefs we must try to find problems and try to correct those problems. Try not to devote all your efforts on justification trying to proof that you are right. Try to criticise your belief to get new beliefs. By a little exercise of cleansing our mind of prejudices and scrutiny can we be able to move in the right path of knowing what is true and what is false. Here I have used the phrase "in the right path" because we don't know what is the end truth - the absolute truth. To say that we have the total truth (the total or complete truth doesn't exist in my view) is to say that we are now stoping here - stoping progress in that area.

All in all our source of knowledge has to be pure, like an innocent eye [as Karl Popper says] we have to look at the truth. Any impure source, i.e. having apriori position, leads to ignorance [Plato]. 

Scrutiny and Doubt helps :)

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The Friend

I often recall, it was summer of 2006 I guess, someone asking me about "who is your best friend"?

To which my reply was "I have never considered that option".

Those days perhaps my imature-materialistic views had no place for a best friend. Later on (in early 2012) I came across the following definition of a friend by Christopher Hitchens, and after that it started making sense. I have been with some wonderful people whom I now call "The Best Friends".

“For me, (writes Hitchen) to remember friendship is to recall those conversations that it seemed a sin to break off: the ones that made the sacrifice of the following day a trivial one.” In support of this, he adduces several staves of William Cory’s translation of the poem by Callimachus about his beloved friend Heraclitus:

THEY told me, Heraclitus, they told me you were dead, 

They brought me bitter news to hear and bitter tears to shed.
I wept as I remember'd how often you and I 
Had tired the sun with talking and sent him down the sky

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