Apr 192010

Last month Intel released their new line of enterprise-class x86 server processors, the Xeon 7500-series “Nehalem-EX” processors. This is very significant, as their existing enterprise x86 processors (7400-series) were getting quite old and were not particularly competitive. The new Xeons provide much higher computational performance, as well as many enhancements for reliability, availability, and serviceability (RAS). They are immediately available in 4-socket configurations and will also be appearing in 8-socket configurations.

With a product this complex, it’s very difficult to cover every aspect of the new design. I will be focusing primarily on the performance of the new processors, with a particular focus on HPC as that is the market with which I’m most familiar.

To the best of my knowledge, the Xeon 7500s are some of the most diverse processors released under the same name. Their core counts range from 4 to 8, with clock speeds ranging from 1.87GHz to 2.67GHz and L3 cache ranging from 12MB to 24MB. This makes the decision of which processor to purchase more difficult than ever before, as one can’t easily determine which processor is “best”. You have to carefully evaluate your application and requirements, as well as the capabilities of each model.

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Feb 042010

Kids love to watch movies, but they are not kind to equipment. Some of the older media, such as VHS tapes, might be technically inferior to DVDs but they certainly were more durable. We have tried to get our kids to carefully handle DVDs, but it just doesn’t happen. A few were destroyed before I learned my lesson.

It turns out that most geeks with kids have realized the same thing: you just can’t give kids DVDs. All the films and videos they love can be stored on your hard drive with much better results: no more messing with scratched discs, no more fumbling for the right video case, instant access to whichever video they want to watch, and you won’t have to replace broken DVDs over and over (something which will make our corporate overlords very unhappy).

This had been working well for us until I tried to save the new Pixar film Up. A quick bit of googling revealed that movie studios have attempted a new form of disc copy protection: ship broken discs.

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Oct 012009

You may not often think about it, but the appliances/tools/toys/etc that we think of as hardware have many software components – and almost all software has bugs or idiosyncrasies. If the manufacturer fulfilled their duty and properly tested the device, you hopefully won’t find a bug. But humans are ingenious – through malice or ignorance, a user will likely try something “out of the box”. When this happens, the results vary: a bug in your microwave can hurt you, a bug in your car can kill you, and a bug in your ATM will cost you money.

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Sep 292009

You may know of Moore’s law, which predicts that electronic transistor density will double every 2 years. This prediction has been accurate for decades, and is often taken as a law of nature. The results: cheaper, faster computers every year are a staple of modern technology and life. We expect constant improvement will continue indefinitely. But how long can this continue, and what should we expect to see years down the road?

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Apr 142006

Most people have probably heard jokes about debugging computers. The modern term refers to removing accidental mistakes made during the programming process. Historically, insects were actually found inside computers. The first recorded incident was a moth that shorted a vacuum tube. Unforunately, it can still happen in the literal sense if you’re not careful.

Most modern computers require high speed fans to cool the complicated, power-hungry components. Some reach speeds of 15,000rpm, which is pretty dangerous if anything is caught by the blades. I just witnessed some small insects being sucked into, chopped up and spit out by these high speed fans. It’s very strange to see insect parts spewed into the inside of a computer case, with some pieces stuck to the sides. I never thought about computers collecting things other than dust.

Mar 012006

You don’t often think about it, but many appliances/tools/toys/etc that we think of as ‘hardware’ have many ‘software’ components – and almost all software has bugs or idiosyncrasies. Unless you think a bit outside of the box, you hopefully won’t notice. This is really a good thing – a bug in your microwave probably won’t kill you. A bug in your car, on the other hand, really can kill you.

The oddity I’ve noticed in my microwave is that I can set it for any number of seconds. So, I can heat my food for 0:60, 1:00, 0:90, 1:30, etc. I can even set it for 1:99. It doesn’t reduce the utility or safety of the appliance, but it might not be what you expect. This demonstrates the problem: try something the designers didn’t expect and you will get an unexpected result. It happens a lot.

May 172004

The arrangement of keys on a keyboard traditionally follows the QWERTY layout (named for the first 5 keys on the left hand: q, w, e, r, t, y). The QWERTY layout was designed before computers existed, and was used as the layout on Remington typewriters. However, the layout has survived for more than a century with very few, if any, improvements. It is the layout that almost everyone uses, but is it really the best choice?

Another keyboard layout, DVORAK (named after the inventor), was patented in 1932, but has never been widely adopted. Many typists who have tried this layout have been adamant that DVORAK is more efficient than QWERTY, but others have claimed that DVORAK is not really much of an improvement. Additionally, switching to a new layout would be quite an inconvenience for most typists. Is a DVORAK layout more efficient, and is it worth making the transition from QWERTY?

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