X-bit labs

Knowing the Depths: NVIDIA GeForce 6600 GT Architecture

Category: Video

by Tim Tscheblockov , Alexey Stepin

[ 09/07/2004 | 05:30 AM ]

NVIDIA's GeForce 6600-series graphics processing units are now almost here: in a few days, in mid-September 2004, NVIDIA’s add-in-card partners are expected to begin shipments of the new mainstream hero. Let us have a look, what is inside of this graphics processor as well as find out all its strong and weak sides.

Table of contents:

• Introduction
  
• GeForce 6600, Junior in the Family
  
• NVIDIA’s New Mainstream Offer: GeForce 6600 GT, GeForce 6600
  
• GeForce 6600 GT: Taking a Closer Look
  
• GeForce 6600 GT: Noise, Overclocking, 2D Quality
  
• Testbed and Methods
  
• DivX, DVD, HDTV Playback
  
• GeForce 6600 GT: Theoretical Tests
  
• Fill Rate Tests
  
• Pixel Shader Performance
  
• Vertex Shader Performance
  
• T&L Emulation
  
• Relief Rendering and Other Theoretical Tests
  
• Synthetic Tests: Conclusion
  

Introduction

Until the present, NVIDIA Corp. has been having problems with arranging a comprehensive line-up of modern graphics processors. The company had an excellent chip for making top-end and upper-mainstream graphics cards out of, but the mainstream sector was only represented with outdated solutions of the unfortunate GeForce FX brand. Meanwhile, ATI Technologies, the archrival, had competitive enough RADEON 9800 XT series graphics cards that had moved down to the mainstream sector after the release of the new RADEON X800 GPU family.

The GeForce FX architecture was inferior to the competing solutions from ATI in many respects, so NVIDIA got to develop a chip that would bring the GeForce 6800 functionality down to the new mainstream. Today, on September 7, the new product is officially released, and you are welcome to be present at the delivery. As might have been expected, the new one obtained the name of GeForce 6600, which tells of a relation to the top-end GeForce 6800 family and negates any tie to the obsolete GeForce FX series.

GeForce 6600, Junior in the Family

The GeForce 6600 is architecturally alike to the GeForce 6800 and boasts all of the latter’s capabilities, including support of Shader Model 3.0, high-precision dynamic range (HPDR), UltraShadow II and other technologies we detailed in our review of the NV40 core. Thus, NVIDIA is a pioneer again, now issuing the world’s first mass GPU with support of the new pixel and vertex shader standard (as you remember, the NV40 was the first GPU to offer support of Shader Model 3.0, so the company’s maintaining its technological superiority). Besides that, the GeForce 6600 became the first of NVIDIA’s products to have native support of the PCI Express bus. Until now, all PCI Express compatibles from NVIDIA were connected to this bus via a special bridge chip. The full list of the GeForce 6600’s characteristics follows below:

The new GPU has 8 pixel pipelines and 3 vertex processors (against 16 and 6, respectively, in the GeForce 6800 Ultra), and this allows getting along with a lower transistor count. One GeForce 6600 die consists of 143 million transistors only. Compare this to the GeForce 6800 Ultra’s 220 million. The new GPU is manufactured with the most advanced 0.11-micron tech process, developed and implemented by Taiwan Semiconductor Manufacturing Company (TSMC).

The lesser complexity of the die and the thinner tech process mean better heat dissipation and power consumption parameters as well as a higher chip yield. We hope the situation with the acute shortage of GeForce 6800 Ultra/GT won’t recur with GeForce 6600-based cards.