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Well, we certainly saw this coming. For the last several years, every generation of graphics card has followed pretty much the same pattern. About six months after a new graphics chip architecture is released, we get the “kicker” version. This clocked-up variant takes advantage of better manufacturing processes and slight redesigns of the silicon to squeeze out a few more MHz, and hopefully, a decent bit of extra performance. It’s just about time we saw these pumped-up variants based on the GeForce 6800 line and the Radeon X800 series.

nVidia has not yet announced the clock-enhanced variant of the GeForce 6800 series, but today ATI shows their hand. The Radeon X850 XT Platinum Edition, previously known by the codename R480, is a clocked-up version of the Radeon X800 series of cards. We put the new flagship product through its paces, so let’s see how it performs.

The main difference between the X850 XT Platinum Edition and the X800 XT is clock speed. For the time being, this new card is only available in PCI Express (PCIe) format, and it surpasses the previous best PCIe offering from ATI by a reasonable amount, if you don’t count the Platinum Edition X800 XT cards that were almost exclusively the domain of OEMs. The X800 XT weighed in at 500MHz with a 500MHz memory clock speed. The new X850 XT Platinum Edition defaults at a slightly more substantial 540MHz with a 580MHz memory clock. This seems like a pretty modest 8% clock speed improvement for the core and more substantial 16% for the memory, but it’s not that simple.

While the 500/500MHz X800 XT was the fastest commonly available PCIe card out of ATI’s house, there was a Platinum Edition card available to OEMs, as well as an AGP version of the Platinum Edition that was available (though extremely hard to find) at retail. Those cards came at a clock speed of 520MHz with 560MHz memory. Compared to that, this new card delivers a very modest boost in clock speed—less than 4% on the core and memory.

How did ATI come by these new clock speeds? The new chip is not simply a re-spin of the R420 chip that powered X800 cards, we are told. This new design features some architectural tweaks that take advantage of some of the improved thermal characteristics of ATI’s notebook designs as well as some manufacturing process improvements at TSMC. Still, the chip is produced with a .13 micron Silicon-on-Insulator process, so not much has changed there.

No, the most obvious and substantial new feature of the new flagship Radeon is its new cooling solution. Gone is the single-slot heat sink and fan used on previous ATI boards. In its place is a dual-slot solution reminiscent of recent high-end nVidia-based products. The larger heat sink and fan are shrouded in clear plastic, forcing air to be pulled in from the back end of the card and out the front. The bad news is that this new double-wide solution is going to have the same problems with those little small form factor PCs that nVidia’s high-end boards have had. We’re big fans of the little cube PC, so we’re sorry to see the single-slot cooling solution go. The good news is that this more substantial cooling solution really isn’t any louder than the old one. Our ears couldn’t really detect any difference between the two—the loudest fan in our test system is still on the CPU cooler.

The X850 XT PE isn’t the only new PCIe card ATI is taking the wraps off today. Also new is the Radeon X800 XL, a cheaper card for more budget-conscious enthusiasts. Here’s a quick comparison of ATI’s high-end products, with the new introductions highlighted.

X850 XT PE X850 XT X850 Pro X800 XT PE X800 XT X800 Pro X800 XL X800
Pixel pipelines: 16 16 16 16 16 12 16 12
Core/memory clock: 540/590 520/540 TBD 520/580 500/500 475/450 400/490 392/350
MSRP: $549 $499 $399 $549 $499 $399 $349 $249

Note: Columns in grey represent the new GPUs.

Certainly, some of the X800 cards will be replaced by the new variants at similar price points. You’ll see a lot of crossover in the marketplace for the next several months, though. At press time, ATI has still not quite nailed down the clock speeds of the X850 Pro, but judging by the price, we expect something around 450MHz core and 500 to 520MHz memory. Not all these cards are quite ready to flood the market just yet; today we’re just taking a look at the top dog.

So there’s really not much new sauce in a Radeon X850 XT PE. That’s unfortunate, but the improvements in clock speed could still make it “king of the hill” in the increasingly competitive world of high-end consumer graphics. We took ATI’s new top dog and pitted it against their previous best commonly available PCIe card, and nVidia’s, to see what kind of improvement it delivers. Our test system was as follows:

CPU: 3.4GHz Pentium 4 Extreme Edition
Motherboard: Intel 925CXV
Memory: 2GB 533MHz DDR2 RAM
Audio: Sound Blaster Audigy 2 ZS
Hard drive: Maxtor 1250GB S-ATA hard drive
Optical drive: Plextor PX-504UF
Operating system: Windows XP Pro w/SP2
DirectX version: 9.0c

In this machine we tested three cards in turn. The new X850 XT PE was pitted against the previous best PCIe card, the X800 XT. Since the Platinum Edition version of that card was generally only available to OEMs, we went with the regular version—the fastest PCIe card you can actually buy without a new computer. nVidia’s best PCIe card is the GeForce 6800 Ultra, which is actually clocked a little bit higher than the AGP version of the same card. Its core clock speed is 435MHz with a memory clock of 550MHz.

With these three cards in the same high-end PCIe based system, we can get a good idea of how well ATI’s new card stacks up against the competition, and how much they’ve improved over their previous high-end offering.

We used the latest drivers for all cards. For ATI, this meant a beta of Catalyst 4.12, the final version of which is due out later this month. For nVidia, this meant the publicly available ForceWare 67.02 beta drivers. We always used the in-game settings for anti-aliasing and anisotropic filtering, where available.

Let’s start off with our synthetic tests. 3DMark05 is an extremely forward-looking benchmark, stressing DirectX 9 more than any current game. Let’s see how the cards stack up in this extremely graphics-intensive test.

Product Radeon X850 XT Platinum Edition
Web Site:
Pros: Relatively quiet; blazing fast; good drivers.
Cons: Very expensive; modest improvement over ATI’s previous best.
Summary: We can’t help but be disappointed by the modest increase in performance, but it’s still the fastest card around. If availability improves, ATI has done their job.
Price: $549