Nvidia NV20 details leak out
Ties in very nicely with DirectX 8.0 developments
Nvidia's next graphics chip, codename NV20, will be the best thing since sliced bread - what new 3D accelerator isn't? - according to specs leaked to ZDNet's German subsidiary.
But while everyone appears to be getting all hot and bothered by the numbers, one small detail proves rather interesting: the chip is programmable.
This is interesting because of recent developments with DirectX. Version 8.0 of Microsoft's games and multimedia API. Earlier this week, head of UK graphics chip developer 3DLabs, Nick Trevett, claimed DirectX 8.0 was going to render - pun not intended - all existing chip architectures obsolete.
Why? Because DirectX 8.0 gives games developers control over the rendering pipeline. Where once accelerator chip designers determined how their silicon would speed up geometry, texturing, shading and lighting, and software writers had to work with that, now the coders can decide how best to organise the pipeline for the needs of their software.
"There is a real discontinuity coming in the graphics market. Applications vendors will decide what the geometry and pixel pipelines look like. It makes every graphics chip in the world obsolete," said Trevett.
Trevett's claim - made in an interview with Electronics Times - has an agenda, of course. It's all about promoting 3DLabs solution to accelerating DirectX 8.0: a programmable chip core.
"We believe it is a bigger discontinuity than between 2D and 3D," he said. "Every time you get a discontinuity, you get an opportunity... We are working to make sure we are one of the first to have a programmable architecture."
And, if the ZDNet Germany leak is anything to go by, so is Nvidia. Interestingly, we asked Nvidia to comment on Trevett's claims - oddly enough, no one from the company chose to speak to us.
NV20 certainly is a DirectX 8.0-oriented chip, supporting the API's pixel shaders, according to the leak. It also adds support for 3D textures - something we'd predicted Nvidia was going to incorporate into its Xbox chip design - high order surfaces, real reflective bump-mapping and layered fogging for much smoother mist effects than has been possible to date.
Nvidia has also built in technology to reduce overdraw - drawing one polygon then drawing another on top it because it's 'closer' to the viewer - which apparently leads to improved performance as the triangle count increases. That, reckons Nvidia, will lead to a two- to sevenfold improvement over the GeForce 2 Ultra, depending on the number of polygons in the image - the more there are, the better the improvement.
Whatever, it should make for an interesting comparison with 3dfx's upcoming Gigapixel-based technology, codenamed Mosaic, which improves performance by focusing on only a small part of the to-be-rendered scene at a time, also an attempt to reduce the impact on performance from all the overdraws 3D chips usually waste cycles on.
The NV20 is also said to offer significantly improved anti-aliasing - it's up to four times faster than the GeForce 2 Ultra.
Much of NV20's performance gains will come from its support of 250MHz double data rate (DDR) SDRAM. The chip's core clock is said to be higher than the GeForce 2 Ultra, which runs at 250MHz.
Both DirectX 8.0 and NV20 give a taster for the technology that will sit at the heart of Xbox, so the console is clearly shaping quite nicely, and Nvidia is doing rather nicely out of its relationship with Microsoft. In processor terms, NV20 does more than one trillion operations per second and 100 billion floating-point ops per second. ®