Author Archives: Chris Samuel

More cores, less speed

Posted on by

An interesting set of simulations at Sandia of multi-core systems have been reported:

A team of researchers simulated key algorithms for deriving knowledge from large data sets. The simulations show a significant increase in speed going from two to four multicores, but an insignificant increase from four to eight multicores. Exceeding eight multicores causes a decrease in speed. Sixteen multicores perform barely as well as two, and after that, a steep decline is registered as more cores are added.

The reason for this is fairly well known, but it’s nice to see numbers put to the effect..

The problem is the lack of memory bandwidth as well as contention between processors over the memory bus available to each processor.

The original Sandia press release has more information.

Taxing Questions for Liechtenstein

Posted on by

I was listening to the BBC From Our Own Correspondent Podcast which had a great piece by John Sweeney about murky going ons in Liechtenstein. Part of it made me think that they’ve been going to the same school as Microsoft:

The next morning we heard that there was a banking seminar at the university on openness. This being Liechtenstein, the openness meeting was closed, at least to us.

John also has a wicked sense of humour..

Imagine my disappointment on discovering that Liechtenstein was, in fact, the most boring place on earth. I’m used to boredom – I work for the BBC, for heaven’s sake – but Liechtenstein was as dull as ditchwater, no duller. They bank behind closed doors. They create fuzzy trusts behind close doors. They make false teeth. And then they go to bed. The person who most looked like a ruthless killer was Howard, and he was the BBC producer.

Well worth a listen.. 😉

Happy 1st Australian Birthday to me! ;-)

Posted on by

Today was Australia Day / Invasion Day (depending on your point of view) and it’s the first anniversary of my becoming an Australia citizen.

Didn’t get to do much to celebrate though as we’re in the middle of a massive backup recovery at work which has been keeping me very busy recently (24+ hours of extra work busy to date) and about which I’ll blog more when I get the chance. For now all I’ll say is don’t trust your hardware RAID controller and boy am I glad we’ve got good backups! 🙁

ENOKOGAN – Kogan Agora is dead (for now)

Posted on by

Oh well, so much for the dream, this was on the Kogan blog this afternoon:

I’m disappointed to have to tell you that the Kogan Agora has to be delayed indefinitely. This delay comes due to potential future interoperability issues.

Sounds like this was partly due to wanting to keep the device compatible with future Android versions needing better screens:

One of the potential issues is the screen size and resolution. It seems developers will be creating applications that are a higher resolution than the Agora is currently capable of handling. […] In order to fully appreciate the feature-rich applications Android developers will be creating in coming months and years, the Agora must be redesigned.

I hope that whatever they come up with still has a real keyboard..

btrfs for 2.6.29

Posted on by

This news from Chris Mason on the linux-btrfs mailing list:

Hello everyone,

Just a quick note that Linus merged the btrfs unstable repository into the mainline kernel. I’ll cut a new stable release of btrfs-progs on Monday to go with it (for now the unstable repo is the best choice).

I’d like to thank everyone who contributed to the code, tested, reviewed, documented, helped organize and otherwise helped Btrfs get as far as it has. It wouldn’t have been possible without you.

There is a lot of work to do before we can really declare Btrfs finished, but this is a huge step forward.

Yay! Congratulations Chris.. 🙂

For those who want to know more about btrfs, please check out its wiki page..

Echo suppression fix for Qt Extended 4.4.2 on OpenMoko Neo

Posted on by

I’d previously posted a patch for echo suppression for Qt Extended on the OpenMoko Neo, but it was completely bogus! 🙂

So I went back to the drawing board and changed it to use the AT%N0187 command to enable both noise reduction and echo suppression in one hit as I worry that the original method of using a command for each would result in the previous command being undone. I also added them to a couple of other places where
they looked like they’d be important such as on initialisation and on wake from suspend.

I’m using a slightly earlier version of the attached patch (only removed two comments and inserted some blank lines) on my Neo at the moment and it seems to be working fine – on a test call from a train I was told there was no echo (with the volume at max and mic gain right up) but that I “sounded like I was in a bathroom”, i.e. there was a bit of reverb. 🙂

I’m not convinced that it’s completely foolproof as I don’t know if it’ll remain enabled if I get two incoming calls without a suspend in between.

But it’s still a lot better than what I’ve been having to put up with since I got this going!

I’ve attached both the echo patch to this post and the compiled version of the Neo plugin that is running on my phone. To use it you will need to scp it onto your Neo and then:

root@om-gta02:~# cd /opt/Trolltech/Qtopia/plugins/phonevendors/
root@om-gta02:~# mv libneovendor.so libneovendor.so.orig
root@om-gta02:~# mv /home/root/libneovendor.so .

Once you’ve done that reboot the phone and you should be using the new version!

Attachments

Extreme Ironing

Posted on by

You’ve heard of lots of extreme sports by now and probably the Extreme Games, but you’ve probably not heard of Extreme Ironing..

The sport that is ‘extreme ironing’ is an outdoor activity that combines the danger and excitement of an ‘extreme’ sport with the satisfaction of a well pressed shirt. It involves taking an iron and board to remote locations and ironing a few items of laundry. Our Guinness World Record attempt will be for the most number of divers underwater ironing at the same time.

It’s being done to raise money for the UK’s lifeboat organisation (and registered charity) the RNLI and is on the 10th January 2009 at the UK National Diving & Activity Centre near Chepstow.