X-bit labs

Highly Defined: ATI Radeon HD 2000 Architecture Review

Category: Video

by Anton Shilov , Yaroslav Lyssenko, Alexey Stepin

[ 05/15/2007 | 07:34 AM ]

The sixth-generation ATI Radeon series has mirrored the release of the third-generation Nvidia GeForce – having been scheduled for a Q4 2006 release, the highly anticipated R600 is coming out in Q2 2007, half a year after its main opponent. Will the R600 be a new R300 or follow the fate of the NV30? Let’s check it out right now!

Table of contents:

• Unified Shader Architecture – ATI’s Vision
  
• Ultra Threaded Dispatch Processor Version 2.0
  
• When 64 Equals 320: Unified Shader Processor of ATI Radeon HD 2000
  
• Radeon HD 2000 Texture Processor: Enough Is Enough?
  
• Ring-Bus Memory Controller: Implementing 512-bit Bus
  
• Render Back-End: Now with Accelerated Stencil! 
  
• Evolution of FSAA: Now Up To 24x!
  
• Avivo HD: FullHD Gets to PC
  
• Back to the Future: Hardware Tesselator
  
• Radeon HD 2000: The Family Portrait
  
• ATI Radeon HD 2900 XT: PCB Design
  
• Cooling System Design
  
• Faster, Louder, Higher: Noise Level and Power Consumption of Radeon HD 2900 XT
  
• Testbed and Methods
  
• Anisotropic Filtering and FSAA Quality Investigation
  
• Performance in FSAA Modes
  
• Performance in Theoretical Tests
  
• Scene Fill Rate
  
• Pixel Shader Performance
  
• Vertex Shader Performance
  
• Other Theoretical Tests
  
• Conclusion
  

Microsoft Windows Vista, DirectX 10 and the unified shader architecture were all being discussed as far back as when DirectX 9.0 was just released, but it was only in late 2004 that the important transition for the whole industry was brought up to the public. It is then that ATI Technologies and Nvidia first talked about the unified architecture as applied to their GPUs. The latter was traditionally keeping all the info to itself, dropping occasional comments like “we’ll transition when it’s really necessary”, but the former openly declared its intention to migrate to a unified shader processor architecture.

In fact, ATI and Nvidia were both transitioning to the new architecture in steps, smoothly. Particularly, ATI introduced a universal dispatcher of computing resources for pixel processors (called an ultra-threaded dispatch processor) into the Radeon X1000 series and Nvidia began to experiment with different frequencies for different parts of the graphics core back in the GeForce 7. Although Intel, S3 Graphics and Silicon Integrated Systems do not disclose their plans, Intel’s current integrated graphics core is known to have unified shader processors while S3 and SiS are developing their products with such architecture, too.

Thus, the transition to the unified shader architecture was not something unexpected for any of the active GPU developers. It was part of a long-established plan. Talking about ATI Technologies, this plan was realized in the Xenos GPU that was installed into the Microsoft Xbox 360 console.

Nvidia was the first company to introduce a GPU with a unified architecture, though. It was the November 2006 announcement of the GeForce 8800 series. ATI, which has now become the graphics division of Advanced Micro Devices, is lagging behind with their R600 chip by over half a year notwithstanding their earlier experience with the Xenos. Just like it was with the Radeon X1800 series, the company unveils an entire family of DirectX 10-compatible chips: R600, RV630, and RV610.

In this article we’ll talk about the special features of ATI’s new architecture and Radeon HD 2900 XT chip. We will also try to understand what is the cause of ATI being so late with its DirectX 10-compatible GPUs. Have they been preparing something revolutionary or just correcting software/hardware problems and bugs?