AMD ATI Radeon HD 2000 Series Architecture

Introduction

AMD is announcing today its new ATI Radeon HD 2000 Series. This is the first series from AMD/ATI featuring DirectX 10 and five desktop models were announced: Radeon HD 2900 XT for the high-end market (previously known by its codename, R600), Radeon HD 2600 Pro and XT for the mid-range market and Radeon 2400 Pro and XT for the low-end market. While Radeon HD 2900 XT can be found on the market starting today, the other models are just “paper launches”, as they will be released by the end of June, with no specific date set yet. In this article we will explore the details of the new architecture brought by this new series.

It is very important to note that several architecture improvements that are being announced by AMD and by other media refers only to Radeon HD 2900 XT, not being valid for the other two families, HD 2600 and HD 2400.

For a better understanding and comparison with previous technologies, we recommend you to read other two articles, ATI Radeon X1000 Series and GeForce 8 Series Architecture.

Here is a summary on what is new on this family. On the following pages we will talk specifically about the architecture used on each family.

• Shader 4.0 model (DirectX 10). Click here to understand what is new on this new programming model.
• Because it is based on Shader 4.0, it uses a unified shader architecture, where instead of having separated processing units for pixel shader, vertex shader, physics and geometry, it has several “generic” processing units (also called “stream processors”) that can handle any kind of processing. These processors run at the same clock rate as the chip (on GeForce 8 series they run at a different clock rate, higher than the rest of the chip).
• 128-bit HDR (High Dynamic Range). Radeon X1000 series only supported 64-bit HDR. Competing chips from NVIDIA use 128-bit HDR since GeForce 7 series.
• New generation of Avivo – dubbed Avivo HD –, the 2D enhancements from AMD/ATI, featuring HDMI support built-in the graphics chip – i.e., without using an external chip. With an adapter any DVI connector on HD 2000 series-based boards can be transformed into a HDMI connector supporting digital audio output, feature not present on any other video card on the market to date.
• New anti-aliasing mode called Custom Filer Anti-Aliasing or simply CFAA, available up to 24x, competing with Coverage Sample Anti-Aliasing (CSAA) available on GeForce 8 series from NVIDIA.
• Native CrossFire on Radeon HD 2600 and 2900 families.
• 80 nm manufacturing process on Radeon HD 2900 XT and 65 nm manufacturing process on the other models. In fact this is the reason why Radeon HD 2900 XT is being released right now and the other models aren’t.
• New power saving features for the mobile models, called “PowerPlay 7”.

Let’s now talk about the specific architecture and features of each family announced today.