3dfx Interview (September 1999)

Again we are not here to discuss the features of our next products, however clearly we plan to offer substantial benefits which go above and beyond the current Voodoo Graphics architecture (T-Buffer is a good example of something we’ve already disclosed). What is important, however, when we add new features is that we do so in a completely backward compatible manner so that our customers can continue to run all the games already available for 3dfx products.

When can we expect an announcement and/or shipment of such a product from 3dfx?

Unfortunately we can’t really get into the details of future products at this time. We have detailed some of the new functionality of those parts in the form of the T-Buffer, which we believe is very exciting for the industry. We have said that the first product to incorporate the T-Buffer technology will be available for Christmas.

We will support full AGP texturing in forthcoming products. However, it really is a moot point at this stage because AGP texturing is not being embraced (nor has it ever been) by the development community. There simply is not enough bandwidth on the AGP bus, even with AGP 4x, to sustain high fill-rates when texturing from AGP system memory. What has happened is that as polygonal complexity increases, the additional AGP bus bandwidth is used up for polygon traffic. And, the continual decline in memory prices has made having to store textures in system memory less and less of an issue (witness that you can buy 32MB graphics boards now for under $100). And, even Intel is backing off from its strong support of AGP texturing for the same reasons I outline, so I think you’ll see moving forward it becoming a very unimportant "checklist" feature….

By and large, anything which improves the rate at which data can be transferred from the CPU to the graphics device is a very good thing. AGP 4x Fast Writes certainly fall into this category. What I am still confused about from the GeForce announcement is how they actually utilize AGP 4x Fast Writes when they’re running a game. Remember that a large part of 3D graphics performance is being able to build up large command streams which can then be processed by the 3D accelerator as fast as it can. Traditionally in nvidia’s architectures, these large command streams are created in AGP system memory and then automatically read by the 3D accelerator from AGP system memory and then executed. In that scenario, AGP 4x Fast Writes never come into play because the CPU is writing directly to AGP system memory, and then the graphics device is simply reading from AGP memory using traditional AGP read commands. So, unless nvidia has radically changed their command interface mechanism, which we do not believe they did, they actually might not even use AGP 4x Fast Writes during a real-world game scenario (i.e. not a canned benchmark). We’re looking forward to finding out more about this.

We have seen very little developer interest in any of the bump mapping techniques that are supported in DirectX 6. Quite frankly, we thought there would be more interest, but developers don’t seem to be embracing it. We believe that the difficulty of implementing bump-mapping properly in an application is likely the reason why there are such few titles which take advantage of the capability, in addition to a host of visual artifact problems which all the currently-announced bump-mapping techniques exhibit.