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Japanese Company Puts Together 800 TFLOP GPU for Real-Time Ray Tracing

Paul Lilly — Tue, 07 Jul 2009 08:30:59 -0500

Think your dual-GPU GTX 295 videocard is anything to write home about? It's still the king of desktop videocards, but it does't come anywhere close to offering 800 teraflops of processing power. That's the amount a Japanese company has to work with, which has mashed together nine 73-core chips into a single system. And as daunting as that may sound, it fits inside a typical ATX desktop setup.

Before anyone asks, the answer is 'no,' it won't run Crysis. Not because it can't, but because it's not aimed at gaming. Those 800 TFLOPs of number crunching provide real-time ray traced rendering and is being aimed at automotive design.

As for how the 45nm super GPU works, Arstechnia has put together a fantastic article describing all the gritty details, includng the complex bus directing all that traffic. Give it a glance here, then tell us what you'd like to use this kind of GPU computing power for (Folding, anyone?).

Image Credit: davidlarkin.files.wordpress.com

Caustic Graphics Demos Their Ray Tracing Processor

Andy Salisbury — Tue, 21 Apr 2009 18:40:02 -0500

In today’s world of gaming hardware, ray tracing is the epitome of gaming graphics. Sadly, rendering them is difficult for current hardware due to their extremely random nature. Caustic Graphics is fixing that issue, all thanks to their graphics co-processor, the Ray Tracing Processing Unit (RTPU).

The RTPU works alongside current 3D graphics processors to bring rays at frame rates acceptable for interactive applications. While the offered 3-5 frames per second works for these applications, it’s nowhere near what gamers require. Thankfully, they claim that their second generation of hardware, out sometime next year, will be able to deliver 14 times that frame rate.

Be sure to check out a video of the tracing in action here.

Image Credit: Caustic Graphics

More Research Required Before Ray Tracing Practical for Games

Paul Lilly — Fri, 22 Aug 2008 11:11:54 -0500

3DFX changed the gaming landscape forever when it brought 3D graphics to the masses, and in a similar fashion, ray tracing technology looks to be the next big revolution on the horizon. The promise of photo realistic scenery has provoked both developers and gamers, but is real-time ray tracing in games anywhere close to being a reality?

In an interview with Tom's Hardware, Intel's Daniel Pohl talked about the API Intel is using to showcase ray tracing demos and what he thinks needs to happen before the technology will be ready for commercial development.

"Creating higher image quality even faster. That requires smart anti-aliasing algorithms, a level of detail mechanism without switching artifacts, particle systems that also work in reflections, a fast soft shadowing algorithm, adoption to upcoming hardware architectures. We have some topics to keep us busy," said Pohl.

In the case of ray tracing, it's a matter of the hardware needing to catch up with the software. Pohl and his team of ray tracing researchers have been "targeting future architectures that consists out of tens, hundreds, and even thousands of cores," noting an almost linear scaling of frame rates with the number of processor cores.

Intel isn't the only one looking to push ray tracing technology into the mainstream, with Nvidia putting on demonstrations of its own. Here's hoping the race to the finish line ends up resembling more of a sprint than a marathon.

Image Credit: Gillis Tran

Nvidia Shows Off Interactive Ray Tracing Demo

Justin Kerr — Sat, 16 Aug 2008 16:06:34 -0500

Nvidia’s secret war with Intel has evolved into a full scale arms race for the atomic bomb of graphics technology, ray tracing. Using its forum at SIGGRAPH, Nvidia was able to demonstrate an interactive ray tracing simulation using four of the company's next-generation Quadro GPUs. They were set in a Quadro Plex 2100 D4 Visual Computing System with an estimated street price of around $11,000. Not exactly your standard gaming rig, but it gets the point across. Either way, it appears as though Nvidia is finally taking a cue from Intel and is focusing at least some of its effort on developing hardware capable of making this technique a reality for everyday users. The demonstration featured linear scaling of an anti aliased Bugatti Veyron with over two-million polygons. It was run at a resolution of 1920x1080 (1080p) and chugged along at an impressive 30 FPS. The demonstration also featured image-based lighting paint shaders, reflections / refractions, and ray traced shadows. Industry insiders noted that the demo was an impressive undertaking since it was one of the first interactive demonstrations done using a GPU. Intel has demonstrated ray tracing using Quake 3 but was done using CPU power. Larrabee will be Intel’s counter in the consumer market, but it remains to be seen if the CPU style design will be as capable of pushing out polygons as Nvidia’s offerings. Gamers are no doubt hoping the new race to master ray tracing will accelerate its development, but I have a feeling we will be playing Duke Nukem Forever long before we see consumer based ray tracing solutions from either company. Though the important first steps are now well underway.

Want to read more about ray tracing? Read Maximum PC’s White Paper: Raster vs Rays.

White Paper: Raster vs. Rays

Zack Stern — Mon, 21 Jul 2008 18:42:14 -0500

The shiny, new hatchback you nudge in a street race dents slightly on the driver’s side door. Although you’re playing a PC game, created with beaucoup equations, the bend looks almost real. The 3D renderer sculpts all those numbers into images, with help from the video API (application program interface). However, several completely different rendering techniques can be the source of those images. Currently, the hardware and software industries are debating how to best utilize two graphics-rendering techniques: ray tracing and rasterization.

Rasterizing is widely used to render current 3D games because it strikes a compromise between real-time processing demands and pretty pictures. Its regular, predictable patterns are also suited to specialized massively parallel processors, such as GPUs. Essentially, the raster engine looks at the thousands of 2D triangles that build a 3D scene and determines which are visible in the current perspective. With that information, the engine analyzes the light sources and other environment details to light and color pixels onto each triangle.

Ray tracing takes the opposite approach, borrowing from the way photons move in the real world. In nature, a light source creates countless photons (or rays) that bounce off objects, take on their color and properties, and eventually reach your eye.

Ray tracing reverses the process, firing its gaze away from the camera perspective, assessing which objects are in view. When a ray hits something, the engine knows to draw a pixel.

The Grey Area

These two techniques further diverge when adding shadows and other details to a scene. Rasterized graphics can use a few techniques to create light and dark, frequently relying on shadow maps. These guides are created by rasterizing from the perspective of a light source, seeing which objects are visible, and shading the camera perspective based on this blueprint. A ray tracer calculates shadows just by tracing more beams and seeing how they bounce. If a beam’s path leads back to a light source, its pixel is drawn brighter. If the beam ends without hitting a light, the engine knows to draw that pixel in shadow.

Ray tracing’s realism—and system burden—comes from the arbitrary point at which the engine stops calculating these bounces. Every time the beam ricochets off another object, more color, shadow, and reflection details can be added back to the first collision pixel. Fog effects can be especially taxing, requiring the beams to refract through a mist. The best-looking images can take billions of rays; that’s just too much number crunching for today’s CPUs and GPUs to handle in real time.
And even if those chips could keep up, other bottlenecks couldn’t keep pace with a fully ray-traced real-time scene. “It’s just too hard in terms of memory bandwidth; it’s too hard in terms of silicon speed,” says David Kirk, chief scientist at Nvidia. “It’s just too hard. And I don’t think that’s the goal.”

“Graphics in general is the grand art of cheating,” Kirk notes, regardless of technique. “We’re trying to approximate what nature does—tracing gazillions of photons around—by doing less work than that, because even the most sophisticated and powerful ray tracers don’t trace billions of rays per second.”

Tools For The Job

“This whole CPU versus GPU distinction is a little bit artificial,” says Bill Mark, senior researcher at Intel’s Corporate Technology Group. “Certainly you can build GPUs that have some CPU-like characteristics. Similarly, you can build CPUs that have GPU-like characteristics.” That said, ray tracing slightly favors current CPUs because those chips were designed for similar computations as the physics-based ray engines.

Jerry Bautista, co-director of Intel’s Tera-scale computing research program, says, “There’s no computational difference between tracing the path of a bullet and tracing the path of a light ray.” That similarity could even lead to ray-tracing engines being recycled as a game’s physics engine, saving programming and processing power. Bautista also notes, “General compute engines like a CPU are pretty well suited to physics kinds of problems, whereas a GPU is more of a stream compute engine and probably a little better suited to… processing triangles at a high speed.”

Ultimately, hardware companies want software developers to have access to the fastest parts, regardless of renderer. Intel is developing its massively scalable, multicore Larrabee architecture. Nvidia is offering ways for game developers to run their own rendering code directly on the video hardware, allowing even those GPU devices to accelerate ray tracing.

Bright Future

According to Intel, hardware one to two generations away could render a complete, real-time scene with ray tracing. But nobody sees that as the goal. Nvidia’s David Kirk says, “If you could do all ray tracing, would you? I don’t think you would. There are many effects that you can do that involve diffuse kinds of lighting—that means softer, more inter-reflected kinds of lighting—that are horrendously [taxing]… to do with ray tracing.”

The hardware companies want to give software developers more opportunities to write their own renderers, mixing and matching methods even within a single scene. Like the current process in many animated movies, a rasterizer could sketch in a game scene, while a ray tracer could add sharp reflections and details.

This mix-and-match approach seems to contradict an API standard, but Microsoft has already been heading toward this solution. DirectX even allows game developers to send programmable shaders directly to the graphics card, allowing open-ended acceleration regardless of the 3D engine. Chas Boyd, principal program manager for Windows Display and Graphics Technology notes, “In future releases, we will continue to increase the generality of [Direct3D], and thus offer developers even more flexibility in their choice of rendering methods.”