June 26, 2007

5.95 KW/TFlop

The next world's biggest scientific computer will be yielding 500 teraflops and consume 3 MW of power. Which comes out at approximate 6KW per TFlop. Which is much worse than the IBM BlueGene (if they delivered the performance envisioned). We need a Moore's law for power per operation but it seams we're going nowhere as far as power use is concerned.

Posted by Claus at 01:20 PM | Comments (0)

June 25, 2007

Too bad the word Twitter is taken

Whistle while you work.

Posted by Claus at 06:13 PM | Comments (0)

1 TB disks about to appear

Seagate is set to start shipping 1TB disks. For those keeping score, that's about 3 times the disk space in the first public edition of Google. Note: I'm pretty sure the bandwidth to the disk is not keeping up - disks like this new 1TB disk get their relevance from large files not lots of files.

(Bonus: The 1998 Salon story where I first heard of Google)

(Bonus II: Carrying one of these home from the office would provide a sneakernet bandwidth of approx 4 Gbit/s)

Posted by Claus at 02:57 PM | Comments (2)

James Clark blogs on XML

The father of Expat and Relax NG now has a blog where he talks a lot about XML and JSON.

Posted by Claus at 02:48 PM | Comments (0)

June 21, 2007


The Mono team pulled a 21-day 12-16 hour-per-day hackathon to implement Silverlight for Linux that they have dubbed Moonlight. 21 days with a group of good hackers doing double shifts and working on the weekends. Just counting hours, each contributor will have put in about as much work as a regular 9-5 employee does in two months. We're assuming the entire team is composed of clever people - only clever hackers care to work so much. And lets assume there's a handful of people working on it (seems reasonable from the task list). So about a years worth of quality development delivered in 3 weeks by a small committed team with no external constraints and full concentration.

Sounds about right to me. Miguel de Icazas war story blog post is a great read.

Posted by Claus at 03:51 PM | Comments (0)

All of Denmark covered by 100$ wifi router

One has to guess extra antennas were involved - and no forests or other natural antennae in the way - but the lowly and standard Linksys WRT54 router was recently used in an experiment able to transmit WiFi over a 382 km distance.

Posted by Claus at 12:42 AM | Comments (0)

June 15, 2007

How to switch off the broken ruby readline on Windows

It took me > 2 hours to remember this from machine A to new machine B just recently so here goes:

Ruby on Windows ships (many versions, any way) with a broken readline used in irb and rails console sessions. The upshot of the broken readline is that the characters { [ ] } and | are not available - which makes it kind of hard to use blocks...
The trick is this:
In your .irbrc file in c:\Documents and Settings\Your Name (make one if it isnt there) put the single line

IRB.conf[:USE_READLINE] = false

and your console sessions should become more satisfying

UPDATE: Hmm - through the unbelivable idiocy of the ruby distro on windows, ruby actually does NOT read this .irbrc on its own, and I haven't found a solid default interpretation of ~ or HOME or HOMEPATH elsewhere on win32 ruby either
You have to
set IRBRC=c:\Documents and Settings\Your Name\.irbrc
No, placing it with the ruby interpreter itself doesn't help either

Posted by Claus at 03:58 PM | Comments (0)

June 07, 2007


LOLCode lets you hack in absurd ALL CAPSy LOLCats glory. The code samples are great.

Posted by Claus at 01:12 AM | Comments (0)

June 06, 2007

Convert hardware PCs to virtual PCs

Excellent: VMWare actually has a free tool to convert physical OS instances to virtualized OS instances. This is the kind of thing you always thought should just work in an ideal world - but tends not to in the real world. Anybody have any experience on how well this actually works? It seems to.

Posted by Claus at 01:08 PM | Comments (0)

June 04, 2007

3TB memory cache

Facebook's memcached cluster has over 3TB of ram on 200 boxes. Obviously if you did a full memory count for Google's entire cluster you would reach enormous numbers, but still - as single installations of addressable ram goes 3TB is a big number.

Posted by Claus at 02:22 PM | Comments (0)

Citizens for a stateless web

The protocol version of the statement the web should be a public place is "HTTP is and should remain a stateless protocol". There are software reasons to make it so - and IMO digital freedom suggests its a good idea as well.

Posted by Claus at 02:05 PM | Comments (0)