AMD Re-Affirms Commitment To Micrsoft's DirectX API


Despite numerous online reports’ suggestion to the contrary earlier this week, AMD says it is committed to supporting Microsoft’s Direct X application programming interface (API) on its GPU hardware for gaming.

Bit-tech.net last Wednesday reported that AMD's worldwide developer relations manager of its GPU division, Richard Huddy said software developers told him Microsoft’s Direct X was getting in the way of optimal graphics performance for PC gaming. In an interview with CRN on Tuesday, however, Huddy said his comments had been taken out of context and exaggerated. Huddy and Neal Robison, senior director of ISV relations at AMD, said only high-end gaming developers may benefit from going around Microsoft’s API.

“The [Bit-tech] interview started off being about Open GL, and the way APIs are developed,” Huddy said. “Obviously there’s pressure from Microsoft on hardware vendors to develop Direct X in a variety of ways. We spend a great deal of time getting feedback from game developers in the early phase of our hardware development, for products that are two or three years away from going to market.”

During the process of collecting feedback from software developers, Huddy said that a very small number of very high-end developers said they wanted to go around Microsoft’s API. “We’ve received an increasing number of requests from some game developers to get around the limitations of the API,” he said. “The problem is that games have converged on a particular kind of solution for a particular kind of hardware, either the Direct X API or Open GL.”

Huddy cited developers including Dice, known for its successful Battlefield series, and Critech are among the minority of game developers who are looking to get around the API. “It’s not something most developers want,” he said. “If you held a vote among developers, they would go for Direct X or Open GL, because it’s a great platform.”

In particular, Robison touted Direct X’s stability and the standardization it has brought to what was a highly-segmented industry. “We saw some of the chaos before Direct X coalesced the industry,” Robison said. “In the past there were all kinds of APIs developers had to worry about.”

In fact, according to Huddy, developers were not the only ones who fell under pressure from the lack of a standard API to simplify the difficult task of game development; hardware vendors like AMD had to do more before Direct X came along as well. “Every single hardware vendor had to worry about producing their own API, or mimic another vendor’s API,” he said. “But there are game developers who would very seriously consider tuning their code for a particular piece of hardware.”

The demand for an alternative to industry standards in game development involves a natural trade-off between stability and high-end performance, according to Huddy. “Direct X provides a highly stable platform,” he said. “It’s hard to crash a machine with Direct X, as there’s lots of protection to make sure the game isn’t taking down the machine, which is certainly rare especially compared to ten or fifteen years ago. Stability is the reason why you wouldn’t want to move away from Direct X, and differentiation is why you might want to.”

Next: A Means Of Differentiation Huddy said that for some high-end developers, developing their own API may allow them to do improve the performance of their gaming while others may see it as a different approach and a means of differentiating themselves from the competition. “The minority of developers who want a change fall into two categories: those like Dice who have highly-tuned, efficient rendering engines, and those like Critech who are selling hardware and could differentiate themselves quite spectacularly from mainstream gaming by going around Direct X,” he said. “Some may be able to do spectacularly good gaming, but for an engine vendor it might simply be a good reason to diverge over the next five years or so.”

Huddy said a difference of opinion has emerged in the industry between those who believe in Microsoft’s API and those who would like to go another direction -- and AMD must pay attention to both. “Many people are still shipping DX9 games, which is still a perfectly reasonable way to go,” Huddy said. “As hardware vendors we want to keep bringing out new hardware that produces something visually exciting. We want to be able to innovate. In the feedback we’re getting, some say ‘move on from Direct X’ and some say ‘DX is absolutely the right place to play.’”

Huddy repeated the point he made in last week’s article that GPU platforms on the PC far exceeded console GPUs in terms of performance, but added that APIs and other middleware for gaming have to innovate and adapt with evolving software code as well as GPU hardware. “If you take the Xbox 360, it’s absolutely dwarfed by modern hardware -- a game on a PC will always have a relatively thick software layer, a console does not.” he said. “We’re putting a lot more horse power at the high-end. But the software layer that lies between the PC running Direct X and the game itself needs to get involved in a lot of transformation.”

As for the point about software developers wanting the API to go away, Huddy said that should not be taken literally. “Making the API go away doesn’t actually mean there is no longer any API,” he said. “They would take a different form.”

Next: The Peculiar Personality Of Game DevelopersHuddy said that if developers think going around Direct X will help improve the performance of their GPUs, they can also turn to an alternative to Direct X that provides less in the way of stability. “High-end developers could use a different kind of API much more like Open CL that gets at just the computer hardware, but doesn’t have the notion of a Z-buffer,” he said. “The Z-buffer is the fundamental surface algorithm we apply to PCs. So long as you could extend Open CL to expose Z-buffering or texture-filtering, you could actually expose all of the hardware and greatly increase performance on current games.”

Aside from the technical challenges and the need to support different kinds of capability on AMD hardware, Robison said part of developing an ecosystem around the GPU involves acknowledging the mindset of software developers. “We love our game developers,” Robison said. “But there’s definitely a personality that goes along with being a really good game developer, and that’s the notion that ‘I can do everything better myself.’ In the quest for the ultimate PC gaming experience, there’s always that notion. But there are only a few people in the industry that could really handle the complexities of programming the hardware that Direct X takes care of for the vast majority of developers.”

Another aspect of developing the ecosystem, according to both Robison and Huddy, involves communicating what is needed to the software vendor, in this case Microsoft. “Yes we absolutely put pressure on Microsoft in the same way that they put pressure on us,” Huddy said. “This is an ecosystem.”

Huddy cited the words of an executive at rival chipmaker Intel to describe the mentality of GPU hardware vendors. “We live in a desperate situation, every day is a desperate situation for us,” Huddy said. “We require that our software partners make use of our silicon, otherwise we are creating dark silicon that no one gets value from,” Huddy said. “AMD needs to innovate, as a gaming company and as a CPU company. Microsoft needs to do the same thing. We’re making sure that the synergy between us is a highly cooperative one. If they were to say ‘graphics is a done deal’ that would be a big problem. They haven’t said that.”

Next: The Constant Need For Innovation While AMD will rely on Microsoft’s predictable, stable API, Huddy said, it will continue to innovate to respond to pressure high-end developers. “Direct X hardware does things in a highly predictable way, and it will continue to perform in a very predictable way from one generation to the next and from one vendor to the next,” he said. “If we want to innovate, and make our products better than previous generation, we need to figure out that pressure and handle it.”

Finally, as for the reference to Intel’s Larrabee x86 cores in last week’s interview – in which Huddy said the desire to go around APIs was responsible for the appeal of Larrabee -- Huddy said it allowed Intel the freedom AMD has to write and publish their drivers and give them to developers in source form. “From a game developer’s perspective, it offered really low-level control of hardware, and that’s very attractive to a small group of developers,” he said. “Intel found a couple of problematic things, however. They found that building a GPU is really hard, that it requires a tremendous amount of expertise and experience to make GPUs as efficient as they are on the extraordinary scale that AMD makes them, and they found that writing drivers is hard as well.”

Huddy added that part of what gets in the way isn’t just Direct X or any other API, it can also be AMD’s driver. “It’s very hard to build a driver that’s very fast,” he said. “There are two difficulties: the software and the hardware. But philosophically it’s possible.”

Robison added that despite the philosophical advantage, Larrabee is the kind of product AMD would not offer. “Larrabee was horribly inefficient,” he said. “It required an unbelievable amount of power and offered very little value. There would not be any possibility of a product like Larrabee succeeding in the marketplace.”

Despite the need to put ‘pressure’ on Microsoft, Robison added that AMD sees Microsoft’s Direct X product quite differently. “We’re simply letting Microsoft know the feedback we get from game developers,” he said. “We’ve heard from the high-end and the low-end. The very high-end want something more in terms of performance. That’s information we give to Microsoft. They’ve done a tremendous job continuing to innovate with Direct X. Game developers, AMD and Nvidia offer constructive feedback because we want to see them continue to innovate.”