Introduction

While everyone loves to read about the latest $500 graphics cards from ATI and NVIDIA, the real volume of the market comes from the mainstream price segment. These are the $150-$200 graphics cards such as the GeForce 6600 GT and RADEON X700 PRO, both of which are doing quite well in terms of sales right now due to their exciting price/performance ratio: both of these cards are faster than last year’s high-end $500 cards in some situations.

However, lying just between the high-end, flagship cards and the less expensive mainstream cards is the most exciting segment of them all: performance mainstream. Often times, these $250-$400 cards contain most, if not all of the same features found in the high-end $500 cards, only they run at slower clock speeds and/or perhaps with less memory; giving you most of the performance of a flagship card only with a much lower price tag.

X800 XL AGP and GeForce 6800 GT AGP reference board

AGP versions of the X800 XL and X800 XT

X800 XL AGP flanked by its PCI-E counterpart and the X800 XT

ATI’s RADEON X800 XL is a perfect example of this. Its R430 graphics core supports the same 2.0b shaders as ATI’s high-end X850 cards, as well as all sixteen pixel pipelines. ATI even equips the X800 XL with a 256-bit memory interface with 256MB of high-speed GDDR3 memory. Feature-for-feature, the RADEON X800 XL is right up there with the latest $500+ ATI graphics cards, only it sells for hundreds of dollars less (the MSRP on PCI-E boards is $300, while AGP cards retail for $350).

To make the chip cheaper to manufacture, ATI uses a smaller 0.11-micron manufacturing process, which in turn means they have to sacrifice a little clock speed. For instance the X850 XT Platinum Edition’s performance-optimized 0.13-micron process allows it to clock in at 540MHz, while the X800 XL tops out over 100MHz slower, at 400MHz. Our overclocking endeavors with six different X800 XL cards in our X800 XL roundup last month revealed that most cards maxed out around 420-435MHz, with two cards hitting over 440MHz, but none over 450MHz, leaving the X800 XL well short of the X850 XT PE’s stock speed. Without low-k dielectric and the other optimizations found in TSMC’s 0.13-micron process, the X800 XL just can’t scale to higher clock speeds. ATI ran into similar problems with the X700 XT’s simpler 8-pixel pipeline architecture early on (which uses the same 0.11 process), the chip just didn’t yield well at 475MHz. We saw this just recently in our Sapphire TOXIC X700 PRO review (which uses leftover X700 XT cores), as the card just didn’t overclock well past 500MHz.

To cut costs further, ATI uses cheaper, slower memory for the X800 XL; 2.0ns memory modules clocked at 500MHz are used on X800 XL boards, while X850 XT PE boards ship with faster 1.6ns modules operating at 590MHz.

While these changes prevent the X800 XL from besting the X850 XT PE in performance, it still comes quite close to matching the PE board, especially in CPU-bound applications such as flight sims. Even in titles such as Half-Life 2 the X800 XL is able to deliver 90% of the X850 XT PE’s performance in most situations, it isn’t until you hit 1600x1200 that the Platinum Edition board really begins to pull away.

Because of this, the X800 XL is an excellent candidate for enthusiasts looking to upgrade. The only problem is that up until now, the X800 XL has only been available in PCI Express format. While PCI-E delivers twice the theoretical bandwidth of AGP, today’s games just haven’t been designed to take advantage of this, resulting in little or no performance improvement. With millions of AGP systems already out on the market, these consumers may not want to spend the extra money for a PCI-E motherboard to go along with the PCI-E graphics card until the applications are there. These users would rather just upgrade their AGP graphics card and call it a day.

Hence the need for the X800 XL AGP was born.