The Radeon 9800, 9600 and 9200

Introduction

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It must be happy days over at ATI right now. Not only is the GeForce FX late and just barely edges ahead of the 9700, ATI is now ready to release their next batch of chips aiming squarely to make sure the FX never has the time to become King-of-the-hill.

A few weeks ago I was invited to a little pressmeating here in Stockholm with ATI where they presented their new line of chips: the Radeon 9800, the Radeon 9600 and the Radeon 9200.

DX9

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Before we talk about the new chips lets talk about DirectX9. The new Radeon 9800 and the Radeon 9600 both not only support DirectX9 but have support for some extra features. ATI jokily called it DX9(++) support in response to NVIDIA’s claim that the GeForce FX has DX9+ support.

The High-End

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The Radeon 9800 is the new flagship from ATI. While not a revolution it is an evolution from the 9700. Let’s take a look at some of the interesting fact about this chip:

Specifications:

• Supports DX9 and OpenGL2.0
• It is 0.15um and not 0.13 as some rumours have suggested
• The Radeon 9800 Pro is clocked at 380/680 MHz. Compare this to the 9700 pro (310/325 MHz). Right now I do not have info about the clockspeed of the regular Radeon 9800.
• 2.0 Vertex Shaders support vertex programs up to 65,280 instructions with flow control surface support
• 2.0 Pixel Shaders support up to 16 textures per rendering pass
• New F-buffer technology supports fragment shader programs of unlimited length
• 128-bit, 64-bit & 32-bit per pixel floating point color formats pixel shaders with video data
• The main difference compared to the 9700 is the support for Smartshader 2.1, Smoothvision 2.1 as well as HyperZ III+.

Smartshader 2.1

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ATI has upped the ante in the ‘shader-race’ with NVIDIA. The Radeon 9800 supports Smartshader 2.1. This means:

Compared to the GeForce FX the 9800 has some advantages:

The new F-buffer technology makes it possible to execute pixel shader programs with an unlimited number of instructions, without the costly performance overhead associated with multi-passing the rendering pipeline. As I’m no tech-wizz I will let ATI tell you more about it:

“The F-buffer, short for “Fragment-stream FIFO buffer”, is the first hardware implementation of an idea proposed in a paper by graphics researchers William Mark and Kekoa Proudfoot at Stanford University (http://graphics.stanford.edu/projects/shading/pubs/hwws2001-fbuffer/). It handles complex effects by passing only the pixels that require multi-passing through the pixel shader engine multiple times, while doing all the other steps in the rendering pipeline just once per pixel. Multi-pass pixels are stored in the F-buffer between passes, rather than writing them out to the frame buffer, so transparent pixels can have foreground and background colours stored separately. This technique saves rendering time, reduces memory bandwidth requirements, and gracefully handles transparency”

While it might be hard to understand what the Smartshader 2.1 support really means I guess it can be summarized with “More complex effects, better performance”.

Smoothvision 2

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Just like the Radeon 9700, the Radeon 9800 supports up to 6x AA and 16x anisotropic filtering. It also supports AA Gamma Correction. In the Radeon 9800 ATI has improved performance of both AA and anisotropic filtering.

Hyper Z III+

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Not much to say about this. They have improved the memory bandwidth efficiency as well as optimized the Z-cache to enhance the performance of shadow volumes by better optimizing it to work with stencil buffers. The last point might not be so important right now since not many games use stencil buffers for shadows but games like Doom3 are expected to start using this more heavily.

Conclusion Radeon 9800

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As I said in the beginning the Radeon 9800 isn’t a revolution but an evolution of the Radeon 9700. That isn’t necessarily a bad thing but it means that anyone with a Radeon 9700 pro should take a close look at the benchmarks to see if it is worth upgrading. To help you make an educated opinion about the performance you can read my first review of the Radeon 9800 Pro which will be out in an hour or so. The first benchmakrs show that the Radeon 9800 does draw ahead of the radeon 9700 with 10.30% depending on the resolution and what AA and anisotropic filtering that has been used. Stay tuned for more!.

The Radeon 9800 Pro will be available in March and the RSP will be $399. Add the usual VAT of your country to get an approximation of the price.

Later in Q2 the regular Radeon 9800 will be out (RSP $349) as well as a 256 MB Radeon 9800 pro which will sport 256 MB DDR2 memory (RSP $499). When question about the need for 256 MB ATI had no problem admitting that this was overkill right now but they pointed to the fact that 128 MB was considered overkill a while ago when the first 128 MB boards came out. Doom 3 will definitely take advantage of the extra memory.

Ok, that was the highend. Let's move on to the mainstream.