If you’re at the show, you can also have a chance to walk away with one of two free BUGbundles! Just look for any of us (we’re wearing BUG shirts) and we’ll give you more information. UPDATE: The Win-a-BUGbundle at SCALE 7x survey is up!

See you there!

You can watch the video below (first ~30 minutes are my presenting, rest of the time is Q&A), or you can check out the slides (also below) – but I will say the deck doesn’t really “work” without the voiceover.

Lastly, don’t forget the FREE BUGBUNDLE CONTEST is still live until this coming Friday! So easy to enter…

Live Streaming by Ustream.TV

The video doesn’t necessarily capture all the slides, so if you want to see them raw (read: out of context), here they are:

Our current stack is based on phoneME Advanced, a configuration not available in Open Embedded. That forced us to look at other options as we started working with Poky. The original prototype of the BUG used JamVM and and GNU Classpath, but we have been using phoneME for quite a while. Now was a perfect opportunity to look at other VMs. The obvious alternative is JamVM, but we also tested the Cacao virtual machine due to its support by the Jalimo and OpenMoko projects.

It seems not many people have been comparing VMs on ARM recently so some benchmarks were in order. We based our tests on this article on benchmarking. Our three benchmarks were Scimark2, Linpack, and startup time comparison.

First up was Scimark2, the most comprehensive of the benchmarks. The suite runs various algorithms and reports these scores in mega-flops per second. It also makes a composite score of these tests. JamVM is the clear winner. While Cacao has solid performance on the Monte Carlo prime number finding algorithm, it falls behind in all of the rest of the tests. PhoneME seems to be about 10-20% slower than JamVM in most tests.

Next up was the Linpack benchmark. The first graph is a measure of the speed of the processor in mega flops per second. The second graph is the overall time for running the benchmark so lower is better. Again here we see the same order as the Scimark2 tests. JamVM runs on top for both tests followed by phoneME and Cacao.

Finally, our startup time test. Starting up the OSGi stack currently takes a few seconds, so startup time of the VM has a significant impact on the overall boot time. For this benchmark we started up the Concierge OSGi framework – though it did not load any bundles since we had not ported all of them to the new build system at the time.

Here JamVM performed as expected with an impressive startup time. Note that this is not a constant time, these gains will increase with a larger load. When starting up our full OSGi stack you will probably gain a few seconds with JamVM.

All of this makes it look like the best choice is JamVM, but there are a lot of variables that are swept under the rug above. Most importantly, a 20% difference on a synthetic benchmark does not indicate a 20% improvement in end user experience.

Second, there are some differences in the configurations. We ran these tests using GNU Classpath on JamVM and Cacao. Keep in mind that GNU Classpath is J2SE-like in size, while phoneME Advanced is significantly lighter. This will make a big difference on a benchmark that measures full system performance. These benchmarks are designed for CPU throughput so the additional overhead of Classpath does not show up. However, both Cacao and JamVM can run with phoneME rather than Classpath, it is just not the default behavior in OpenEmbedded.

Perhaps the biggest red herring stems from us not building phoneME with JIT right now. This is due to a problem with older versions of the Linux kernel. With the new build system we will build phoneME with JIT which will gain significant performance. These benchmarks are comparing the current build of phoneME to the Cacao and JamVM default setups in OpenEmbedded, we are not comparing the maximum performance that can be squeezed out of each VM.

Finally, on Thursday Matthias Klose was able to get OpenJDK built for ARM. We will have to take a look at its performance as soon as we have it running on the BUG.

We still are very excited to see the community based VMs performing so well. While there are more factors to consider when choosing a JVM implementation (such as TCK validation, branding concerns, and community support) JamVM definitely warrants a look for anyone interested in embedded Java development on ARM based systems, it certainly impressed us. Look here for a follow up post sometime in the coming months.

]]> http://bugblogger.com/java-vms-compared-160/feed/ 13 http://bugblogger.com/bug-bof-oscon-158/ http://bugblogger.com/bug-bof-oscon-158/#comments Wed, 23 Jul 2008 20:16:35 +0000 Ken Gilmer http://bugblogger.com/?p=158 I’ll be doing a BOF in room F150 at OSCON on Thursday at 8 PM.  For those interested I’ll give a brief technical overview of the BUG device and answer questions.  Please stop by if you can!

If there was ever a great indication of the power that is/will be open source hardware, this is it. TechCrunch announcing they want to build their own Web tablet device. Just awesome. A couple of years ago, Jeremy Toeman (our marketing guy) and I were sitting around thinking about the future and Jeremy actually said – “I bet in the not too distant future we’ll be buying gadgets from bloggers”. I don’t think he meant it literally, though in this case he seems to have been right, he meant that it’s not such a stretch to think that individuals, and not just big corporations will be able to make and sell gadgets economically. If you look at what bloggers have done to big media, it didn’t seem too outlandish. The power to make things is moving from traditional producers to consumers in just about every industry. It’s a profound shift.

I think this is just the tip of the iceberg. And we’re excited to see it happen. Anything we can do to contribute to their success we will.

For those of you that were unable to make it to our first two Open Houses, or for those that have been anxiously awaiting the next one, we’re opening the doors again on Wednesday the 9th from 6 to 8PM. This will be your last chance to check out our current digs, as we’re moving to a new location further south on Broadway in just a few short days.

Why spend your Wednesday night at our humble office? Because we’ll have cool BUG applications and other demos to show off. You’ll get a chance to play around with the hardware and we’ll be on hand to talk about the SDK, BUGnet, applications, stuff you’re interested in building, whatever you like. Perhaps most importantly, there will be beer. There might even be a free T-shirt or two as giveaways (distribution methods of aforementioned T-shirts still pending). No matter what your reasons for stopping by, we’d love to see you.

You can find us at 915 Broadway (between 20th and 21st) on the 11th floor, at the end of the hall in Suite 1109. Look for the fancy red Bug Labs sign on the door.

1. Both are built using open source technologies and ideals
2. Both use the GPL
3. Both start good but get tremendously better with a developer community
4. Both are fully extensible, with practically no limitations to the final product (Guy Kawasaki launched a business, Truemors, purely by customizing wordpress!)
5. Both are “blank canvases” for creation, which could result in a motion-controllable slideshow playback device or… pictures of cats with bizarre captions

We’re working the kinks out of the system now, so you may see an oddity here or there (if so, please do leave a comment on this post!).