X-bit labs

ATI RADEON X1000: Brand-New Graphics Architecture from ATI Explored (page 2)

Category: Video

by Alexey Stepin , Yaroslav Lyssenko, Anton Shilov

[ 10/05/2005 | 12:05 PM ]

Please Meet: ATI RADEON X1000

ATI didn’t have much freedom in choosing the name – “RADEON X900” was the only position left vacant in ATI’s former product nomenclature. Unlike NVIDIA, ATI Technologies used three-digit numbers in the product names of the RADEON X series. But the marketing men from ATI found a simple and elegant way to bypass this problem by adding the number 1000 to the numeric markings of the new products. Thus, ATI’s new graphics processors got the names of RADEON X1800, RADEON X1600 and RADEON X1300. Thus, the names are indicative that we deal with a new-generation architecture, and the company has also reserved enough names for its future products.

RADEON X1800 core

This time “new” in “new-generation” really means it. While NVIDIA’s G70 was a greatly improved NV40, the RADEON X1000 is a completely new architecture that has little in common with ATI’s previous generations of GPUs. By the way, the senior model of the family, RADEON X1800 (R520) chip, is more complex than the NVIDIA G70: 320 against 302 million transistors!

Note that the RADEON X1600 (RV530) targeted for the mainstream market segments consists of 157 million transistors, while RADEON X1300 (RV515) is claimed to be the first value chip that is built of about 100 million transistors.

The architecture has become more complex due to a number of improvements, including:

• Shader Model 3.0 support
• Redesigned shader processors with a special unit for executing branch instructions
• New memory controller
• Redesigned cache system
• A new way of connecting the chip’s units

A lot of rumors about the new RADEON – sometimes absolutely incredible – have been around all that time, but now we can offer you the precise information:

As you see, ATI Technologies really got to frequencies above 600MHz with its new 0.09-micron tech process although the process doesn’t involve low-k dielectrics. The R520 is no worse than the G70 in any other technological aspect, excepting the number of pixel processors. But the higher frequency should make up for that deficiency. Moreover, the memory of the senior RADEON X1800 works at a huge frequency of 750 (1500) MHz which can theoretically yield an up to 48GB/s bandwidth (ATI quotes a smaller number, 42GB/s).