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July 2008 – Page 2 – Stephen Skory

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Month: July 2008



I have previously groaned about the Tour of California ignoring everything south of Los Angeles. But today it was announced that next years tour will visit San Diego County! The final stage is Rancho Bernardo to Escondido. They must plan a circuitous route as those communities aren't very far apart.

I'm excited.

Car Pit

Car Pit


Today Steve Lynch and I did some exploring off Peñasquitos Park and came across these derelict cars dropped into a small gorge. A VW Beetle, Audi and Ford Explorer (high gas prices, you know) were ones I could identify. There were two others rusted beyond recognition. It looked like after the cars had been shoved into the pit, they had been sledgehammered, to make sure they were really dead, of course. The Beetle was missing its motor, among other things, while the Ford didn't have any seats in it. The Audi was probably a nice car once upon a time, it had a sun roof (or moon depending on trademarks).

I like to imagine this is what might happen if the world order collapses. People just junking once useful and valuable things when you can no longer get gasoline or electricity. Kind of like Mexico.

Update: you can see the Ford on Google Maps.

Tour de France Fantasy Pool

Tour de France Fantasy Pool

For the last few years I've participated in a friendly Tour de France fantasy pool with some friends. We get together, have a barbecue, and pick teams of riders. It's very much like fantasy football or baseball teams. Each team pays $20 to enter, which goes to the winner (naturally). However, the winner is obliged to use that money for a party after the Tour, so everyone wins in the end.

Some years ago an Excel spreadsheet was written to help calculate the scores. It's kind of clumsy and surprisingly un-automated. So I threw together a Python script in an afternoon which is much more automated and puts the results on the web for easy viewing.

Above is the graph of how each team is doing as a function of stage. Along with three friends I formed two teams, "Storky's Bitches" and "The Pump Handles." Neither names were my first choice; I blame Kris Wells. I've never done very well at the Tour Pool, and it's looking like this year will be no different. Of course, it's early, so things may change.

Take a look at the full results page, and check back each day throughout the Tour to see how things are progressing.



Faithful readers will remember me posing with my favorite supercomputer about a year ago. Datastar is going to be turned off in a few months. When it was turned on three years ago, it was the 35th fastest computer in the world, it has since slipped to 473rd. Despite the fact it's no longer the fastest thing around, it works wonderfully, and as I write this, there are at least sixty people logged onto this machine. Everyone I know loves Datastar, and wishes it wasn't going to be turned off. I am starting to move my work and attention to the newer machines. They are faster, and have many more processors, which makes queue times short (which is the time it takes for a job I request to run)

Ranger (credit)

A few months ago, Ranger was turned on. It is a Sun cluster in Texas with 63,000 Intel CPU cores. It is currently ranked fourth fastest in the world. Datastar has only 2528 CPUs (but those are real CPUs, while Ranger has mutli-core chips which in reality aren't as good). By raw numbers, Ranger is an order of magnitude better than Datastar, except that Ranger doesn't work very well. Many different people are seeing memory leaks using vastly different codes. These codes work well on other machines. I have yet to be able to run anything at all on Ranger. For all intents and purposes, Ranger is useless to me right now.

If you look at the top of the list of super computers, you'll see that a machine called Roadrunner is the fastest in the world. Notice that it is made up of both AMD Opteron and IBM Cell processors. The Cell processor is the one inside Playstation 3s. Having two kind of chips adds a layer of complexity, which makes the machine less useful. The Cell processor is a vector processor, which is only awesome for very specially written code. The machine is fast, except it's also highly unusable. I don't have access to it because it's a DOE machine, but a colleague has tried it and says he got under 0.1% peak theoretical speed out of it. Other people were seeing similar numbers. No one ever gets 100% from any machine, but 0.1% is terrible.

A Kraken

Computers two and three on the list are DOE machines, so I don't have access to them. On the near horizon is a machine called Kraken, in Tennessee. It's being upgraded right now, but when it's complete it will be very similar to, but faster than the fifth fastest computer on the list currently, called Jaguar. It is a Cray XT4 that runs AMD Opteron chips. I got to use Kraken recently while it was still an XT3, and it was awesome. Unlike Ranger, it actually works. As an XT4, it should be even faster than Ranger. It will also have a great tape backup system, unlike Ranger.

I am predicting that Kraken will be come my new favorite super computer, replacing Datastar. However, I think it's a shame that Datastar is being turned off even though it's still very useful and popular. When it's turned off to make way for machines like Ranger and Roadrunner(*), that's just stupid.

(*) The pots of money for Ranger, Datstar and Roadrunner are different, but you get the point. Supercomputers aren't getting better; in some cases, they're getting worse!