Date:
Wednesday, August 23, 2006
Author:
Brent Justice
Editor:
Kyle Bennett
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ATI Radeon X1950 XTX / CrossFire Evaluation

ATI is today launching new video cards into several market segments along with the world’s first video card using GDDR4 memory. We cover real world gameplay with the high-end single- and multiple-GPU video cards from ATI.

Introduction

Today’s announcement covers the evolution of ATI’s Radeon X1000 architecture with new video cards for several market segments from value to high-end. Before we begin we want to emphasize that the current AMD buy out of ATI will not be finalized until after the 4th quarter of this year. The proper nomenclature currently for these video cards is still very much “ATI Radeon” video cards and we don’t see that changing anytime soon, you can read about it here, here and here.

For evaluation today we will look at the ATI Radeon X1950 XTX single-GPU video card compared to a single BFGTech GeForce 7950 GX2 as well as an ATI Radeon X1900 XTX. We will compare at 4:3 ratio on a CRT as well as 16:10 aspect ratio on a 24” Dell 2405 FPW at 1920x1200.

For multiple-GPU comparisons we are taking the ATI Radeon X1950 XTX CrossFire combination and comparing it to two GeForce 7950 GX2’s in QuadSLI on a Dell 3007 FPW 30” LCD at 2560x1600.

These are the video cards we will cover in this evaluation. Due to time constraints (we received our cards this past Friday) we are not able to evaluate real-world gameplay evaluations with the other products being announced today. We will follow up with evaluations on the Radeon X1900 XT 256 MB, Radeon X1650 Pro and Radeon X1300 XT.

If you are unfamiliar with the ATI Radeon X1000 family architecture we suggest you head over here and read up on it. We will not go into detail on the architecture, rather just briefly summarize it here. These video cards being announced today are based on the above linked architecture, although one of these new products does use a new GPU codenamed R580+ which we will talk about later.

All ATI Radeon X1000 GPU based video cards fully support DirectX 9.0c and Shader Model 3.0. There is full support for FP16 blending for HDR as well as multisample antialiasing support with FP16 blending which is a unique feature only ATI X1000 family GPUs currently have. All ATI Radeon X1000 family GPUs are based on a 90 nanometer manufacturing process from TSMC and on the high-end models employ over 300 million transistors.

All ATI Radeon X1000 family GPUs support Ultra-Threading which help with dynamic flow control performance. The ATI Radeon X1000 family GPUs use a decoupled shader processing unit architecture which means the pixel, vertex and raster operator processors can operate with unique quantities of each. On the high-end with the Radeon X1900 XTX it has 48 pixel shader processors, 8 vertex processors and 16 raster operators (ROPs). The architecture is laid out so that parts can be scaled down in number to suit GPUs at different price points.

Uniquely ATI uses a new ring bus memory controller on the video card. The goal of this controller was to allow for ATI to expand their GPUs to use newer and faster memory types and gain more benefit from them. This will play into what ATI has to announce today. To read about how the ring bus memory architecture works please read this page.

All ATI Radeon X1000 series GPUs also support ATI’s unique high quality anisotropic filtering option. We have seen very real benefits in the visual quality of games using this feature in our gameplay evaluations. ATI also supports 2X, 4X and 6X multisampling AA, along with a performance and quality Adaptive AA option for performing supersampling on alpha textures. We have covered all of these features in the past so we won’t go into detail exploring them in this evaluation.

That summarizes the current architecture and these new video cards being announced today are based on that architecture. Now let’s talk about what is new.

New Video Card Announcements

Today ATI is announcing new products from the value-end to the high-end. Starting at the high-end you will find the new Radeon X1950 XTX and Radeon X1950 XTX CrossFire Edition. Below that ATI is announcing a new Radeon X1900 XT 256MB video card that will be priced under $300. ATI is also revamping their X1600 and X1300 series with a Radeon X1650 Pro that should be faster than an X1600 XT and a new Radeon X1300 XT which should be the fastest X1300 series yet. We will dive into each product on the following pages with gameplay evaluation following that.