Wednesday, November 26, 2008

Going home

Exams got over yesterday. Though a presentation is remaining. Leaving for home on day after tommorrow.

Sunday, November 23, 2008

Super PC's now availaible off-the-shelf

It seems that the trend of building supercomputers out of multiple gpu's in one pc is catching on. I really like this idea and now nvidia is offering pre-built and qualified systems on those lines. But yes, they come with Tesla series of cards instead of the cheaper geforce cards.

Come on AMD, get your OpenCL implementation working so that we can enjoy much faster super-pc's.

Saturday, November 22, 2008

Good texture compression review

I cam across this very nice review of texture compression. He covers the need for texture compression, and the typical techniques used for texture compression, their pros and cons. Though there are a few spelling mistakes here and there and he builds his case for texture compression around AGP, an extinct bus. All in all, a nice review to aid your understanding of texture compression.

Tuesday, November 18, 2008

AMD's FASTRA now possible

I have written before on how better tools are needed on the AMD side to do gpgpu stuff, in some detail. I had particularly pointed out the need for their drivers to support 4 4870x2 cards in a PC as it makes for a nice 9.6T toaster.

This announcement certainly means that they are stepping up their efforts, though a true C compiler remains in the foggy future. Further, this thread says that they expect drivers to recognize them (the four cards that is) allright.

I saw a few people eager to make such a toaster. Well, with that announcement, good luck guys.

And this suggests that a C-to-IL compiler may not be so far into the future either. Well, good luck guys, give us a C compiler quickly.

Friday, November 14, 2008

India on the moon

Now there's a tricolour on the moon. Great job, ISRO.

Tuesday, November 11, 2008

Multithreading in Python, revisited

I wrote about multithreading support in Python earlier.

Turns out that while python has full support for threads, the CPython interpreter will interpret Python bytecode only one thread at a time, enforcing de-facto serialization of your parallel code.

Come to think of it, it is the worst possible multithreading solution. You get all the problems of parallel programming, and no speed benefit at all. Though could be useful for prototyping alone. It is definitely a bad idea for production code though.

Sunday, November 9, 2008

Multithreading and Python

Came across this fantastic review of various Python VMs out there. Of these, Stackless Python caught my eye particularly.

Native concurrency support. No GIL issues. Point to point message passing for free.

Not bad. Not bad at all.

I have written before on my desire of writing multithreaded code. Due to other demands on my time, that project is still stuck in limbo. But I realized that it will take a lot of work (aka lots of infrastructure code) to get it done. So, naturally, I turned to Python, because

The best code you write is the code that you don't write at all.

Turns out that while python has full support for threads, the CPython interpreter will interpret Python bytecode only one thread at a time, enforcing de-facto serialization of your parallel code.

Not good.

But then you can call multiple extensions from the main thread and have them release the GIL. And after this, extending the interpreter doesn't appear so difficult. A quick google search later I landed here, which shows just how easy it is for all your extensions to release the GIL before launching and re-acquiring it before returning to Python land.

Will take a shot at this way if time permits. I have a few ideas on what to do. But I am not abandoning the classical interpreter for Stackless python just yet. Need to figure out how nicely Stackless Python plays with C extensions before I do that. And of course, there needs to be a fedora package. There is simply no question of compiling the whole thing myself.

Saturday, November 8, 2008

India on Moon

It's done successfully. Our baby is in the lunar orbit. Congratulations, ISRO, you did a great job.