Speeds and Feeds

Have we reached the end of the road for conventional 3D rendering?

Siggraph 2009 ended Friday, and I've spent the last few days digesting what I learned there. Although I've been involved in the graphics industry since 1990 and I've attended Siggraph most years since 1992, a crisis of sorts seems to have snuck up on me.

At the High Performance Graphics conference before the main show, keynote speeches from Larry Gritz of Sony Pictures Imageworks and Tim Sweeney of Epic Games showed that traditional 3D-rendering methods are being augmented and even supplanted by new techniques for motion-picture production as well as real-time computer games.

Gritz reckoned that 3D became a fully integrated element of the moviemaking process in 1989 when computer-generated characters first interacted with human characters in James Cameron's "The Abyss."

Gritz described how Imageworks has moved to a new ray-tracing rendering system called "Arnold" for several films currently in production, replacing the Reyes (Render Everything Your Eyes See) rendering system, probably the most widely used technology in the industry.

According to Gritz, Reyes rendering led to unmanageable complexity in the artistic component of the production process, outweighing the render-time advantages of the Reyes method. But Gritz says even these advantages diminished as the demand for higher quality drove Imageworks to make more use of ray tracing and a sophisticated lighting model called global illumination.

The bottom line for Imageworks is that Arnold, which was licensed from Marcos Fajardo of Solid Angle, takes longer to do the final rendering, but is easier on the artists and makes it easier to create the models and lighting effects--a net win.

Sweeney echoed this theme the next day, which surprised me considering Sweeney's focus is real-time rendering for 3D games--notably with Epic's Unreal Engine, which has been used in hundreds of 3D games on all the major platforms. Game rendering uses far less sophisticated techniques because each frame has to be rendered in perhaps one-sixtieth of a second, not the four or five hours on average that can be devoted to a single frame of a motion picture.

It seems that Sweeney is also ... Read more

Two companies--respectively (I believe) the smallest and largest makers of graphics chips--announced on Sunday that they are developing new standard APIs (application programming interfaces) specifically for ray-traced computer graphics.

Caustic Graphics introduced CausticGL, an API designed to leverage the best aspects of OpenGL, the most widely supported 3D API on the market. CausticGL ties in with Caustic's accelerator chips and boards, which the company says can deliver some 20X the ray-tracing performance of a conventional CPU.

Nvidia offered OptiX (pronounced like "optics"), a name designed to resonate with PhysX, the physics API acquired last year when Nvidia bought Ageia, a company that was developing both the software API as well as a companion accelerator chip. (Nvidia doesn't have a Web page on OptiX yet; I'll update this post when one appears.) (The OptiX page is now online.)

James McCombe (founder and CTO of start-up Caustic Graphics) and Austin Robison (a research scientist with Nvidia) made their announcements in presentations during the Hot3D session I chaired at the High Performance Graphics conference in New Orleans over the weekend. The big Siggraph 2009 conference opens here this week.

The third presentation in the session was from Larry Seiler, a senior principal engineer with Intel, who described new details of how Intel is optimizing 3D-rendering software for its forthcoming Larrabee GPU.

I'll have more analysis of these announcements later, but I didn't want to miss this chance to break some significant industry news.

I spent Tuesday at Nvidia headquarters, attending the company's annual Analyst Day.

I've been to most of Nvidia's analyst events over the last decade or so, since I covered Nvidia almost from its inception while working as the graphics analyst at Microprocessor Report. These meetings are always a good way to get an update on the company's business operations, and sometimes--like this time--one provides exceptionally good insight into larger industry trends.

Nvidia's GeForce GTX 280 graphics chip

(Credit: Nvidia)

Nvidia has had a rough couple of quarters in the market, which CEO Jen-Hsun Huang blamed in part on a bad strategic call in early 2008: to place orders for large quantities of new chips to be delivered later in the year. When the recession hit, these orders turned into about six months of inventory, much of which simply couldn't be sold at the usual markup.

In response, Nvidia CFO David White outlined measures the company plans to take to increase revenue, sell a more valuable mix of products, reduce the cost of goods sold, and cut back on Nvidia's operating expenses.

Three things stood out for me in this presentation:

Nvidia is planning an aggressive transition to state-of-the-art ASIC fabrication technology at TSMC, the company's manufacturing partner. Within "two to three quarters," White said, about two-thirds of the chips Nvidia sells will be made using 40-nanometer process technology. (The first of these chips were announced Tuesday.)

White also acknowledged something that I've long assumed to be true: Nvidia receives "preferential allocation" on advanced process technology at TSMC. It's logical that Nvidia should get the red-carpet treatment, having been TSMC's best customer for many years, but I don't recall hearing Nvidia or TSMC put this fact on the record before.

The third notable point from White's presentation: the gross margins for Nvidia's Tegra, an ARM-based application processor--which Nvidia's Mike Rayfield, general manager of the Tegra division, says has already garnered 42 design wins at 27 companies--are much higher than I'd have guessed--at "over 45 percent." That's quite excellent for an ARM-based SoC; it's a very competitive market.

More surprises
The technical sessions at the event contained their own surprises.

For example, Nvidia effectively seized control of an old Intel marketing buzzword: "balanced."

For years, Intel used to talk about ... Read more

Don't get me wrong-- I think the Intel-TSMC alliance announced earlier this week is a good thing for both companies.

But the official explanation, that Intel wants TSMC's help to make Atom processor cores more widely available to the industry, just doesn't strike me as a sufficient reason for the deal.

Intel hardly needs TSMC's help to make SoCs (systems on a chip). Intel has been making highly integrated devices for the embedded market, as well as PC chipsets for a long time. It already has enough of the building blocks and enough experienced engineers to make Atom-based SoC products.

And it isn't as if Intel needs better process technology, or more fabrication capacity. Intel already has more of the best fabs in the world than any other company.

What's the one thing TSMC can do that Intel can't? Operate with low gross margins. In its most recent quarter, TSMC's gross margin was only 31.3 percent, while Intel's gross margin is still an industry benchmark at 53 percent. The difference is more than Intel's net profit--that is, if Intel had TSMC's gross margins, it would be losing money.

Low-margin component suppliers are a critical element of the embedded-systems market, which Intel identified as one of its target markets for this deal. Cost is king in consumer electronics, so high-margin suppliers like Intel rarely get a chance to participate.

Similarly, as average PC-selling prices decline, a growing share of the demand for processors and chipsets drops into price ranges in which Intel just can't afford to play.

The TSMC deal is Intel's way of taking a piece of these businesses without spending much money or taking much risk. For example, TSMC is already accustomed to helping its customers make SoCs for embedded systems. Intel could build such a business itself, but not at the margins it's used to.

Intel said in its press release that it will be porting its Atom cores to TSMC's technology. This is the sort of work that can get expensive in engineering time, but it's possible that the work will be made easier by a convergence between TSMC's processes and Intel's.

Last May, Intel agreed to cooperate with TSMC and Samsung in the transition to larger 450-millimeter silicon wafers (a little less than 18 inches across, up from the 12-inch wafers used today).

This doesn't necessarily mean that the three companies will co-develop fully compatible manufacturing processes, but with the 450mm transition being slated for 2012, there's still plenty of time left to drop that other shoe.

Anyway, this new TSMC deal is merely at the earliest official stage. The companies have signed a memorandum of understanding, but they have yet to work out the details. That could take a year, and it could be another year or two before Atom-based chips are ready to start rolling through the TSMC factory.

All in all, Atom SoCs might not become available from TSMC until 2012, at which point, they could, in principle, be made on a common Intel-TSMC process.

Not that Intel would provide its really good process technology to TSMC. In chips, as in other things, quality is expensive. Intel's best process technology, which it uses primarily for microprocessors, is at the leading edge of semiconductor manufacturing, with features such as a metal electrode acting as the transistor's gate, a hafnium-based insulation between the gate and the channel, and strained silicon in the transistor channel itself (where the current flows when the transistor is on). (See this Intel presentation for more details. Incidentally, did Intel ever announce which metal it's using? If so, I can't find it.)

TSMC may not need or want any of these features, and it would make sense for Intel to keep its best process technology to itself, anyway, if only to protect its high profit margins.

Even without a leading-edge process, TSMC can still make good money from Atom-based SoCs in the embedded market. That's enough to justify TSMC's participation in the deal.

But I'm not sure that explains Intel's motivation. Sure, Intel will make money it wouldn't have made otherwise, but it will also have costs it wouldn't have had otherwise. Intel may make a few bucks per chip in intellectual-property licensing fees, and perhaps this could amount to hundreds of millions of dollars a year, but that isn't a whole lot of money to a company like Intel, which makes tens of billions of dollars a year in gross revenue.

Why else would Intel be doing this deal?

Well, I think that the chipmaker could be setting itself up to kill off three of its biggest rivals.

There's already an x86 processor company using TSMC to make (some of) its chips: Via Technologies. Via isn't a big player, but it's been a thorn in Intel's side ever since it purchased the x86 processor operations of IDT (WinChip) and National Semiconductor (Cyrix) in 1999.

Via specializes in exactly the kind of processors that Intel can't afford to sell: low-cost, highly efficient designs aimed at low-cost PCs and embedded systems. Today's Atom is better than Via's best chips, but it's also more expensive. A cheaper TSMC-sourced alternative will hurt Via badly.

Most of the same reasoning applies to ARM, which licenses its processor cores to be used in SoCs made at TSMC, among other fabs. That's almost the same business model Intel is adopting with its own TSMC deal.

ARM dominates the market for microprocessors in cell phones. Intel's current Atom processors are too expensive and too power-hungry for that market. But remember, it'll be a couple of years at least before Atom-based chips start shipping from TSMC. The Atom cores of 2011 or 2012 will be more directly competitive with ARM's cores.

So put ARM on the endangered-species list too.

There's one other company that ought to be worried by this deal, and it probably isn't one you'd expect: Nvidia.

Nvidia is generally thought to be TSMC's biggest customer. It doesn't make x86 processors (though there are persistent rumors that the company is developing one), but it does make the ARM-based Tegra family, which would run up against these future Atom chips.

It's Nvidia's graphics chips that I'm worried about, however.

Intel is developing graphics chips of its own under the Larrabee code name. I wrote about Larrabee last August, and it seemed like a bad idea to me at the time. One of my key objections, however, was that graphics chips are inherently a low-margin business due to the strong competition between AMD and Nvidia, and I didn't think that Intel could afford to drag down its margins just to compete in that market.

The TSMC deal changes all that.

Larrabee's cores aren't Atom cores, per se, but they're similar enough that Intel might consider them to be covered by the language in the TSMC partnership announcement. Or if not, agreements can always be expanded later.

Making Larrabee chips at TSMC would solve the margin problem, putting Intel's graphics chips on a level playing field with Nvidia's. Larrabee would still be at a significant disadvantage because its x86-based design isn't as well-suited to graphics acceleration as Nvidia's chips, but Intel has a special ability to sell inferior products along with other chips its customers need--especially processors. That's reportedly how Intel's slow integrated-graphics chipsets ended up in so many systems during the Windows Vista transition, leading to many disappointed customers.

Or it's possible that Intel will not allow the TSMC deal to harm these companies, if only because Intel may still be in court defending itself against AMD's antitrust lawsuit.

But I wouldn't make that assumption, and I bet that ARM, Nvidia, and Via won't either. Intel isn't the only paranoid company in this industry.

Hello, Slashdot.

In a story on PC Pro, Nvidia architect John Montrym (whose name was incorrectly spelled "Mottram") quoted my recent blog post on Larrabee as concluding that "the 'large' Larrabee in 2010 will have roughly the same performance as a 2006 GPU from Nvidia or ATI."

Alas, this isn't really what I said or meant.

What I actually described as equating to "the performance of a 2006-vintage...graphics chip" was a performance standard defined by Intel itself--running the game F.E.A.R. at 60 fps in 1,600 x 1,200-pixel resolution with four-sample antialiasing.

Intel used this figure for some comparisons of rendering performance. If Larrabee ran at 1GHz, for example, Intel's figures show that... Read more

Intel announced on Monday that it will be presenting a paper at Siggraph 2008 about its "many-core" Larrabee architecture, which will be the basis of future Intel graphics processors.

The paper itself, however, has already been published, and I was able to get a copy of it. (Unfortunately, as you'll see at that link, the paper is normally available only to members of the Association for Computing Machinery.)

Intel's Larrabee includes "many" cores, on-chip memory controllers, a wide ring bus for on-chip communications, and a small amount of graphics-specific logic.

(Credit: Intel)

The paper is a pretty thorough summary of Intel's motives for developing Larrabee and the major features of the new architecture. Basically, Larrabee is about using many simple x86 cores--more than you'd see in the central processor (CPU) of the system--to implement a graphics processor (GPU). This concept has received a lot of attention since Intel first started talking about it last year.

... Read more

Dean Takahashi sent me an e-mail pointing to a piece he wrote on VentureBeat describing statements Wednesday by Intel's Chief Technical Officer Justin Rattner targeted at NVIDIA. CNET's own Brooke Crothers covered the same story and provides additional background here.

Intel Chief Technology Officer Justin R. Rattner

(Credit: Intel)

The technology at issue relates to 3D graphics for PCs. All current PC graphics chips use what's called polygon-order rendering. All of the polygons that make up the objects to be displayed are processed one at a time. The graphics chip figures out where each polygon should appear on the screen and how much of it will be visible or obstructed by other polygons.

Ray tracing achieves similar results by working through each pixel on the screen, firing off a "ray" (like a backward ray of light) that bounces off the polygons until it reaches a light source in the scene. Ray tracing produces natural lighting effects but takes a lot more work.

(That's the short version, anyway. For more details, you could dig up a copy of my 1997 book Beyond Conventional 3D. Alas, the book is long since out of print.)

Ray tracing is easily implemented in software on a general-purpose CPU, and indeed, most of the computer graphics you see in movies and TV commercials are generated this way, using rooms full of PCs or blade-server systems.

Naturally, Intel loves ray tracing, and there are people at Intel working to ... Read more