Introduction

Since it was first introduced in 1996, the AGP interface has served the PC well. Over time newer AGP specifications have been introduced offering increased bandwidth, and thus more performance, but now it’s time for AGP to make room for its successor, PCI Express. As one of the leaders in 3D graphics, ATI is poised to release a top-to-bottom family of PCI Express-based products. These graphics cores aren’t just limited to the desktop PC either; in addition ATI is also introducing mobile PCI Express products for the notebook market.

Of course, we all know ATI’s PCI Express plans for the high-end desktop space, RADEON X800 PRO and X800 XT impressed everyone with their excellent performance and new features such as 3Dc and temporal AA. ATI was also quick to remind the world that their X800 line consumed less power than NVIDIA’s GeForce 6800 series and relied on a single-slot cooling design. And of course, it also doesn’t hurt that ATI has beat NVIDIA to market. X800 PRO cards first hit retail in mid-May, weeks ahead of NVIDIA. What does ATI do for an encore? Release more cards of course!

RADEON X600: tackling mainstream

ATI’s RADEON X600, internally codenamed RV380, is designed to address the mainstream PCI Express segment. Unlike its codename suggests, RADEON X600 isn’t a cost-reduced derivative of RADEON 9800/XT, instead its DNA is more closely tied to the RADEON 9600 XT. It sports four pixel pipelines with one texture unit per pixel pipeline and two vertex pipes just like the 9600 XT and the RADEON 9600 PRO before that. The X600 PRO also shares the RADEON 9600 XT’s 0.13-micron manufacturing process with low-k dielectric material.

If you recall, one of the criticisms levied towards the RADEON 9600 XT was its memory subsystem. At 300MHz (600MHz effective), it was clocked the same as RADEON 9600 PRO. To address this, ATI has cranked up the memory to 370MHz (740MHz effective). This change bumps memory bandwidth from 9.6GB/sec in RADEON 9600 XT to 11.8GB/sec in X600 XT, an improvement of just over 2GB/sec. The core clock frequency of RADEON X600 XT is unchanged from its predecessor at 500MHz.

With more memory bandwidth, the X600 XT should be more competitive with NVIDIA’s GeForce FX 5700 Ultra when settings such as anti-aliasing and anisotropic filtering are applied. These were cases where the RADEON 9600 XT’s 500MHz graphics core was starving for more memory bandwidth.

Just below the X600 XT is ATI’s X600 PRO. The PRO utilizes the same graphics core as the X600 XT, only its clocked lower, 400MHz in the PRO board versus 500MHz in the XT. The X600 PRO’s memory operates at 300MHz (600MHz effective), essentially matching the specs of last year’s RADEON 9600 PRO, which also ran at 400MHz core/300MHz memory.

It’s important to note that the X600 line doesn’t incorporate the newer features added to the RADEON X800, 3Dc (compression for normal maps) and temporal AA. The X600 line will also remain exclusive to PCI Express; AGP versions of either card won’t make their way to AGP.