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Showing posts from July, 2010

Hey, you sass that hoopy Fortran?

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We have to work with lots of different Fortran compilers at NAG. So far at Mark 22 of our Fortran Library we have built using products from six distinct sources (GNU, IBM, Intel®, NAG, PGI and Sun). The list of what we build with naturally changes from Mark to Mark as different vendors fall by the wayside or as commercial considerations preclude us from creating a particular Library implementation.

With the six vendors listed above we are blessed that the base Fortran coverage is Fortran 95. At previous Marks we still supported compilers covering only Fortran 77 (g77 and pgf77 for example). This forced us to jump through all manner of hoops so that we could do some of the really useful stuff from Fortran 90—like, woah, dynamically allocating memory—in a Fortran 77 way.

Some hoops still exist though, even with Fortran 90 code.


For example, we recently ran into the following:
PROGRAMstr_read! .. Implicit None Statement .. IMPLICITNONE! .. Parameters .. INTEGER, PARAMETER …

A Life Well-Lived: Erwin Ruppenthal (1958 – 2010)

There’s probably some unwritten rule that blogs are off-limits to memorials. If so, I’m happy to break it for our colleague Erwin (or Erv as he was known at home). He died early this week after a long struggle with brain cancer, at home, surrounded by his wife Heidi and sons Alex and Kurt. If we take a closer look at his life we can learn a lot about the value of work and about having a purpose in life greater than earning a paycheck.Erwin taught me a number of lessons about work and I’ll tell you about some of them so that things he valued might live on in each of us, but first let me tell you a little about him. He came to NAG in early August 1990 to work in IT at our US office. What I’m told was that he was an earnest, hardworking German citizen in his early 30’s who most would describe as shy and self-effacing. It was nine years later that I encountered him on my first day as his boss. He was a man of two countries and two cultures who embraced both. Following sports was a passion…

Time Machines and Supercomputers

I found a Linpack App for the iPhone last week. Nothing special, just a bit of five minute fun. It seems a 3G model achieves about 20 MFLOPS. [Note 1]

What's that got to do with time machines? Well it got me thinking "I wonder when 20 MFLOPS was the performance of a leading edge supercomputer?" Actually, it was before the start of the Top500 list (1993), so finding out was beyond the research I was prepared to do for this blog.

So I thought instead about the first supercomputer I used in anger. As soon as I name it, if anyone is still reading this waffle, you will immediately fall into two camps - those who think I'm too young to be nostalgic about old supercomputers yet - and those who think I'm too old to be talking about modern supercomoputers :-).

It was a Cray T3D.

You're still waiting for the time machine bit ... hang on in there.

My application on that T3D sustained about 25 GFLOPS. Which is about the same as a high end PC of recent years. What this me…

Fantasy Football – a classic Portfolio Optimisation problem

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England out the World Cup, German colleagues, customers, collaborators (actually not just Germans, Americans, Scots,…) and so called friends all sending me mocking e-mails and texts.
“I hear OXO are making a new product. The packaging is white with a red cross and they're calling it the laughing stock.”
How could I channel my frustration? NAG Blog to the rescue.
In my last blog I promised to reflect on my early career at NAG which isn’t that long ago compared with some of colleagues.
My commute to the NAG office is longer than I’d like, but there is a positive side…
·Valuable thinking time ·Audio books - I recently enjoyed “No One Would Listen” by Harry Markopolos. The exclusive story of the Harry Markopolos–lead investigation into Bernie Madoff and his $65 billion Ponzi scheme.
Back to “thinking time,” on one commute into Oxford I’d been pondering the previous day’s internal training course. I was recalling my senior technical colleague’s wise words. That wise colleague was David …

The power within graphics cards

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NAG is a company that likes to be present at scientific events all around the world. One of the main reasons for this is we get face-to-face time with NAG users and this gives us the chance to listen to their needs and reiterate that 40 years on, NAG is still a not-for-profit company for which collaboration is essential.

NAG at the GPGPU Developer Briefing in New York City
Last week I had the pleasure of representing NAG at two events in North America: GPGPU Developer Briefing in New York City and the 6th World Congress of Bachelier Finance Society in Toronto. While manning the NAG stand together with my colleagues we had many interesting conversations with those attending and made them aware of one of NAG’s most recent developments – the NAG Library for GPUs.

6th World Congress of Bachelier Finance Society in Toronto
We expected lots of interest in GPUs at the briefing in NYC, and were all happy to describe our successes with Monte Carlo simulations on GPUs. Currently the NAG Library…