Introduction

ASUS X600 XT meets the ATI reference X600 XT

PCI Express is coming

With Intel’s PCI Express interface finally up and running, graphics card manufacturers are already scrambling to supply the add-in board (retail) and OEM markets with cards.

ATI and NVIDIA have taken different approaches to their PCI Express products. Whereas ATI has taken existing products and modified them for use with PCI Express, NVIDIA has decided to slap a bridge chip on their PCI Express cards. Polling the board manufacturers at Computex last month, all were in unanimous agreement that ATI’s native solution was the better way to go, and the reasons weren’t just limited to performance: NVIDIA’s bridge solution takes up a fair amount of space on the PCB, limiting board manufacturers in the flexibility of their board designs. This is especially important in the value segment, where smaller board designs are frequently used to help cut costs. In fact, many value boards utilize half-height PCBs for this reason.

GeForce PCX 5750, note the heatsink covering the bridge chip

Both boards are based on the same basic design

Adding to manufacturer’s concerns is the heat output of NVIDIA’s bridged design, which requires a heatsink to keep the bridge chip cool. This adds even more to the board cost, and again, plays an even greater role in the value segment, where margins are razor thin.

Because of these factors, ASUS is limiting themselves to just two NVIDIA PCI Express products here in the North American market, the GeForce PCX 5900-based EN5900 and PCX 5750-based EN5750, while they’ve announced half a dozen PCI Express parts utilizing ATI’s RADEON X600 and X300 line of VPUs.

Already retail boards based on the GeForce PCX 5750 and RADEON X600 XT cores have begun shipping and we’ve received samples from multiple manufacturers, while GeForce PCX 5900 and RADEON X600 PRO/X300 should begin to trickle in the coming weeks.We’re here today to review ASUS’ top-of-the-line mainstream offering, the EAX600XT/HTVD.

The ASUS Extreme AX600XT/HTVD is based on ATI’s RADEON X600 XT VPU. While its name implies it’s derived from the X800, fundamentally the X600 XT shares its roots with ATI’s RADEON 9600 XT, which is nothing more than an enhanced RADEON 9600 PRO. ATI has implemented the same 4x1 pipeline configuration found in RADEON 9600 XT, as well as integrating a 128-bit wide memory interface, only the memory’s clock frequency has been increased from 300MHz (600MHz effective) in RADEON 9600 XT to 370MHz (740MHz effective). ATI has kept the core clock frequency at 500MHz.

This change increases memory bandwidth by 2.2GB/sec, which was one of the RADEON 9600 XT’s key shortcomings. As a result, performance is enhanced at high screen resolutions and/or in situations with anti-aliasing or anisotropic filtering in use. In fact, we witnessed performance gains of up to 15% in many games for ATI’s X600 XT over the RADEON 9600 XT in our preview article from last month.

Once again ASUS is looking to differentiate themselves from ATI and other board manufacturers with their X600 XT lineup, much like they did with their RADEON 9600 XT and 9800 XT cards. In fact, in many ways ASUS has built a better X600 XT board than ATI!