Future GPU.org for cryptic Larrabee news

Phil Taylor, a long-time Microsoft graphics and gaming evangelist is now working for Intel on graphics tools evangelism. He started a blog, called Future GPU, where he drops hints and links about Larrabee development. He also tells Microsoft war stories for people in the mood for inside-baseball information about Microsoft’s DirectX and game groups.

Back when I was working at WebTV and just learning about the 3D graphics world, Phil was nice enough to give me and a few of my WebTV co- workers tickets to the super-desirable GDC DirectX party. These parties were intended for external developers, so it was very hard for non-DirectX Microsofties to attend. Thanks Phil!!! :-)

From reading Phil’s blog it sounds like Intel’s developing a set of graphics debugging tools that they’re going to announce at GDC. Could it be PIX-for-Larrabee?

I found Phil’s site through a “Google Alert” that I set up for Larrabee news. It does a weekly search for Larrabee news. The web’s so big and sparsely connected that I’m finding that I’ve never heard of any of the web sites that the Alert is dredging up. Most of the sites mentioned in the Google Alert are not worth visiting, but a few (like Phil’s site) are very interesting indeed.

Pixar Quality Graphics is 720 Gflops

For at least 10 years GPU vendors have been talking about “Pixar Quality” graphics. But what does that mean? Well, according to this lecture on The Design of Renderman, the original goals for the REYES architecture were

  • 3000 x 1667 pixels (5 MP)
  • 80M Micropolygons (each 1/4th of a pixel in size, depth complexity of 4)
  • 16 samples per pixel
  • 150K geometric primitives
  • 300 shading flops per micropolygon
  • 6 textures per primitive
  • 100 1MB textures

That’s a shading rate of 80M * 300 * 30 Hz = 720 Gflops. (They were probably more concerned about 24 Hz, but for games 30Hz is better.)

In comparison I think the peak shader flops of high-end 2008-era video cards are in the 1 TFlop range. (Xbox 360 Xenos is 240 Gflops, PS3 is a bit less.). Now, GPU vendors typically quote multiply-accumulate flops, because that doubles the number of flops. So it’s more realistic to say that 2008-era video cards are in the 500 Gflop range. So we really are entering the era of “Pixar Quality” graphics.

Tech Talk on Wii security model (and breaking it)

A very thorough talk describing the Nintendo Wii game console security model and the bugs and weaknesses that allowed the Wii to be compromised: Console Hacking 2008: Wii Fail

In a nutshell, security is provided by an embedded ARM CPU that sits between the CPU and the IO devices, and handles all the IO. The two main flaws were (a) A bug in the code that compared security keys, such that it was possible to forge security keys, and (b) secret break-once-run-everywere information was stored un-encrypted in RAM, where it could be extracted using hardware modifications.

There’s a nice table at the end of the presentation showing a number of recent consumer devices, what their security model was, and how long it took to break them.

The PS3 is the only console that’s currently unbroken. The PS3’s security model seems similar to the Xbox 360, but somewhat weaker. But it remains unbroken. This seems to due to the existence of an official PS3 Linux port, which means most Linux kernel hackers are not motivated to hack the PS3 security. (Only the ones who want full access to the GPU from Linux are motivated, and only to the extent that they can access the GPU.)

Larrabee papers from SIGGRAPH Asia 2008

…as seen on the Beyond3D GPGPU forum, here are the presentations from the recent (December 12th 2008) “Beyond Programmable Shading” course:

SIGGRAPH Asia 2008: Parallel Computing for Graphics: Beyond Programmable Shading

There are good presentations from both GPU vendors and academics. My favorite presentations are the Intel ones on Larrabee, just because I’m so interested in that architecture:

Parallel Programming on Larrabee - describes the Larrabee fiber/task programming model.

Next-Generation Graphics on Larrabee - how Larrabee’s standard renderer is structured, and how it can be extended / modified.

IBM / Sony missed a bet by not presenting here. That’s too bad, because Cell sits between the ATI / NVIDIA parts and Larrabee in terms of programmability. And Cell’s been available for long enough that there should be a number of interesting results to report.

Note to self: consider buying a PS3 and learning Cell programming, just to get ready for Larrabee. Heh, yeah, that’s the ticket. Being able to play PS3-specific games like Little Big Planet and Flower would be just a coincidental bonus.

Fun with Git

This weekend I reorganize my home source code projects. I have a number of machines, and over the years each one had accumulated several small source- code projects. (Python scripts, toy games, things like that.) I wanted to put these projects under source code control. I also wanted to make sure they were backed-up. Most of these little projects are not ready to be published, so I didn’t want to use one of the many web-based systems for source-code management.

After some research, I decided to use replicated git repositories.

I created a remote git repository on an Internet-facing machine, and then created local git repositories on each of my development machines. Now I can use git push and git pull to keep the repositories synchronized. I use git’s built-in ssh transport, so the only thing I had to do on the Internet-facing- machine was make sure that the git executables were in the non-interactive- ssh-shell’s path. (Which I did by adding them in my .bashrc file.)

Git’s ability to work off-line came in handy this Sunday, as I was attending an elementary-school chess tournament with my son. Our local public schools don’t have open WiFi, so there was no Internet connectivity. But I was able to happily work away using my local git, and later easily push my changes back to the shared repository.

Microsoft New Xbox Experience Avatars

I just tried creating an avatar on Microsoft’s new Xbox dashboard. As you can see (at least when the Microsoft server isn’t being hammered) on the left, they provide a URL for displaying your current Avatar on a web page.

The character creation system is not too bad. In some ways it’s more flexible than Nintendo’s Mii (for example more hair styles and clothing), but in other ways it’s more limited (less control over facial feature placement).

My avatar looks better on the Xbox than it does here – they should consider sharpening the image. For example, the T-shirt my avatar is wearing has a thin-lined Xbox symbol.

I think they do a good job of avoiding the Uncanny Valley effect. I look forward to seeing how avatars end up being used in the Xbox world.

In othe Xbox-related news I’m enjoying playing Banjo Kazooie Nuts & Bolts with my son. All we have right now is the demo, but it’s great fun for anyone who likes building things. It’s replaced Cloning Clyde as my son’s favorite Xbox game.

Internals of the Azul Systems Multi-core Java processor

I’m a big fan of CPU architectures. Here’s a conversation between David Moon formerly of Symbolics Lisp Machines and Cliff Click Jr. of Azule Systems. They discuss details of both the Lisp Machine architecture and Azule’s massively multi-core Java machine.

A Brief Conversation with David Moon

The claim (from both Symbolics and Azule) is that adding just a few instructions to an ordinary RISC instruction set can make GC much faster. With so much code being run in Java these days I wonder if we’ll see similar types of instructions added to mainstream architectures.

Next gen video console speculation suggests we aim low

The next generation of video game consoles should start in 2011. (Give or take a year). It takes about three years to develop a video game console, so work should be ramping up at all three video game manufacturers.

Nintendo’s best course-of-action is pretty clear: Do a slightly souped-up Wii. Perhaps with lots of SD-RAM for downloadable games. Probably with low-end HD resolution graphics. Definately with an improved controller (for example with the recent gyroscope slice built in.)

Sony and Microsoft have to decide whether to aim high or copy Nintendo.

Today a strong rumor has it that Sony is polling developers to see what they think of a PlayStation 4 that is similar to a cost-reduced PlayStation 3 (same Cell, cheaper RAM, cheap launch price.)

Sony PS4 Poll

That makes sense as Sony has had problems this generation due to the high launch cost of the PS3. The drawback of this scheme is that it does nothing to make the PS4 easy to program.

In the last few weeks we’ve seen other rumors that Microsoft’s being courted by Intel to put the Larrabee GPU in the next gen Xbox. I think that if Sony aims low, it’s likely that Microsoft will be foreced to aim low too, which would make a Larrabee GPU unlikely. That makes me sad – in my dreams, I’d love to see an Xbox 4 that used a quad-core x86 CPU and a 16-core Larrabee GPU.

Well, the great thing is that we’ll know for sure, in about 3 years. :-)