Archive for October, 2007

Work from Home

October 28, 2007

As I sit here in my office in Burlington on a Sunday, I realize how much I depend on my laptop to let me work from anywhere at any time. And how much additional work I do because I have that capability.

I’ve been without a laptop for about two weeks. Its replacement should arrive in the next two days (I’ve tracked it from Shanghai to East Boston so far), but not quickly enough to avoid having to drive (40 miles each way) to the office to work on a presentation about code review practices that I’m giving tomorrow.

Aside from that one inconvenience, I’ve come to realize how much work I usually do in the mornings before driving to work and how much I do in the evenings afterward. It makes a big difference in my ability to keep up with everything that needs doing at work.

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Wildfires

October 24, 2007

I hope my friends and colleagues in San Diego and elsewhere in southern California are safe from the flames engulfing the area. Last I heard the air quality was so bad at our La Jolla office that employees were told to go home.

I heard this morning that the Santa Ana winds were abating in southern California, dropping from over 70mph to under 30mph. This sounds promising, though one commentator remarked that as the wind speeds drop, the winds become less steady, and therefore even more dangerous as they constantly shift directions, making the fire-fighting efforts more difficult than they already are.

Best wishes and best of luck to everyone in the affected areas.

The Tailor and the Vegetable Garden

October 16, 2007

[kiva logo]

Last year, Mike Dillon, Sun’s General Counsel, posted a blog entry about micro loans and how he and his wife were using them as a way to teach their kids about the value of giving to others. I decided to give it a try as well, at least in part because micro loans offer a way to directly fund a business venture of significant importance to an individual or family. Using Kiva, I’ve added micro loans to my giving strategy to complement donations I make to other, larger causes. I’m four months into this and I plan to continue this indefinitely.

I’m currently one of 18 people helping to fund the purchase of fertilizer and pest control agents by a mother of four growing a vegetable garden in Mutiatele, Samoa from which she sells produce at local markets. She has repaid 13% of her loan and made all payments on time.

I’m also one of two people funding a tailor, who is using the money to buy more clothing to grow the business he and his wife run in Phnom Penh, Cambodia. He has currently repaid 34% of his loan and made all payments on time.

Once the loans have been completely repaid, I can apply those funds to other outstanding requests for micro loans. I like the Kiva site and will continue to use it, though it sometimes does not have very many loan requests available for consideration.

Liar, Liar, Pants on Fire

October 16, 2007

The Journal of Accountancy is not where I look for interesting articles. Thankfully (but mysteriously) my friend Chris does.

Read this short article for tips on how to determine if someone is lying to you.

Mac Book Pro, Part the Eight

October 16, 2007

My Mac Book Pro started making a new noise a few weeks ago: a soft, but very noticeable, fast clicking sound from the area of the left grill. It sounds like a fan problem (again.) I just boxed up the system this morning and sent it back to Apple for repair, but I’m really hoping they will finally replace the unit. So far I’ve had a DOA superdrive, two bad batteries, a fan replacement, an LCD screen replacement, and a top-case assembly replacement. Read the details of these various problems here.

xkcd: a webcomic of romance, sarcasm, math, and language

October 10, 2007

My new favorite comic: Randall Munroe’s xkcd. What’s not to love about a comic that’s not afraid to delve into regular expressions, cryptographic protocols, grammatical hairsplitting, and iambic pentameter?

xkcd comes with the following disclaimer: Warning: this comic occasionally contains strong language (which may be unsuitable for children), unusual humor (which may be unsuitable for adults), and advanced mathematics (which may be unsuitable for liberal-arts majors).

On blogging…

Regular expressions…

UltraSPARC T2 Systems Exposed!

October 9, 2007

A few photos of our new Sun SPARC Enterprise T5x20 and Sun Blade T6320 systems with their covers removed. Seen today at the employee product launch party here in Burlington. Huron (T5x20) first, then Glendale (T6320).

[huron w/o cover]
[glendale w/o cover]

CMT for HPC: Sun Launches UltraSPARC T2 Servers

October 9, 2007

[ultrasparc t2 chip]

Today we announced our first servers based on the UltraSPARC T2 (Niagara2) processor. They are officially named the Sun SPARC Enterprise T5120, the Sun SPARC Enterprise T5220, and the Sun Blade T6320. For those who enjoy code names, the rack servers are known internally as “Huron,” following in the Great Lakes theme from our UltraSPARC T1-based systems. The blade is called “Glendale.” For detailed specifications on these new machines, start here. UltraSHORT summary: 64 threads, eight floating point units, on-chip 10GbE, low power, 1RU or 2RU or blade form factors. And looking interesting for some HPC workloads.

The UltraSPARC T2 is Sun’s second generation CMT (chip multithreaded) processor. The first-generation UltraSPARC T1, which has 32 threads and only one floating point unit, performs well on many throughput-oriented tasks, but isn’t suitable as a general-purpose processor for High Performance Computing. Some HPC areas like life sciences and some parts of the intelligence community have integer-intensive workloads and can use the UltraSPARC T1 to advantage. For example, see the numerous entries on Lawrence Spracklen’s blog.

So, what can we say about the UltraSPARC T2 and its platforms relative to HPC?

As usual, application performance will depend greatly on the specifics of your application, but having seen the results of several benchmarks on the UltraSPARC T2, I can make some observations. First, remember the primary value proposition of these CMT systems is throughput, and not single-thread performance. We use relatively low-performing cores, but give you eight of them on a single chip, each with multiple threads. Therefore your application or workload must benefit from lots of threads and from the CMT’s ability to hide memory latency by performing real work while waiting for memory operations to complete.

I’ll leave it to the benchmarking folks to give you the official story on exact results and instead make some general observations. First, these new systems generate leading performance numbers on a popular floating-point rate (i.e. throughput) benchmark. However, to achieve those numbers we obviously must run enough instances of the benchmark to make use of all of our threads, which increases the memory footprint and therefore the cost of the system. How much that matters to you in real life depends on how your application’s memory footprint scales in practice.

Consider for example, an OpenMP application. Using OpenMP to parallelize an application leaves the memory footprint essentially unchanged and instead varies the number of threads used within the application. As you’d expect, the thread-rich T2-based systems deliver some very interesting OpenMP benchmark results.

Beyond performance issues, let’s not lose sight of the fact that these tiny boxes have 64 hardware threads (eight FPUs), making them interesting platforms for HPC developers working on parallel algorithms, possibly even for MPI developers wanting to debug their distributed applications on a single machine. And, of course, you should expect to be able to cluster these machines for building larger HPC systems using either the on-board 10GbE or InfiniBand.

For other Sun blogger perspectives on these new systems, start with Allan Packer’s

WaterFire Providence

October 8, 2007

[oracle of waterfire]

The last WaterFire event of the season will be held on Saturday, October 27th. Go for the fire; enjoy the music.