Universal Rule

Book Reviews

Thursday, February 3, 2005

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Shuffling Lightly: "The most interesting thing [about iPod shuffle] is just how light it is." [MyAppleMenu]

We feelings exactly! I thought it would be heavy compared to the tiny size, but it was both tiny and light. I carry it using the lanyard around my neck, and my identity card hanging from the lanyard weighs much more that the iPod shuffle.

Clusters of Xserve G5s -- Comment()
UIUC sets up 640-node Turing Xserve Cluster: "The University of Illinois at Urbana-Champaign (UIUC) is one of the latest educational institutions to set up a high-performance computing (HPC) cluster using Macintosh computers. The university's Turing Xserve Cluster comprises 640 Apple Xserve G5 systems." [MacCentral News]

A reader commented my impressions of the G5 cluster at Virginia Tech regarding my estimate of a factor of 10 difference in the power consumption figures:

The simple answer is two fold.

Peripherals although I don't suspect that's the big area.
Cooling. Cooling is particularly inefficient in such a system and would easily start pushing you up over the MW range. You want around 15 - 20% excess just in case meaning you want a rough operating area of 1.2 MW. Even using liquid cooling somewhere along the line you have to remove the heat and the liquid has to flow. All of that requires pumping, fans and electricity.

This answers seems to have solved the dilemma. Using air for cooling is indeed very inefficient. At work we used to have a liquid-cooled Cray T3E, which was very compact and very easy to maintain despite having 544 processors.

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Hide Your IPod, Here Comes Bill: "To the growing frustration and annoyance of Microsoft's management, Apple Computer's iPod is wildly popular among Microsoft's workers."