Single page Print

ATI's Radeon X850 XT graphics cards


Canadian double-wide?
— 8:00 AM on December 1, 2004

ATI'S HIGH-END RADEON X800 CARDS have been reasonably successful by most measures. The technology is solid and, although a little older, more or less on par with NVIDIA's GeForce 6 series GPUs. They seem to be selling well, with big PC makers like Dell sucking up nearly all the cards ATI can supply. The cards' performance is decent, and ATI's market share numbers are up.

However, not all has been roses. NVIDIA's GeForce 6800 cards have been fierce competition, with the 16-pipe GeForce 6800 GT arguably offering a better value at $399 than the Radeon X800 Pro. Also, ATI's top-end product, the Radeon X800 XT Platinum Edition, has been exceptionally rare. Oh, sure, the streets aren't exactly awash in GeForce 6800 Ultras, but the Platinum Edition has been brutally scarce.

ATI is aiming to correct these availability problems and bring a little more performance to the X800 series with a pair of new graphics chips, code-named R430 and R480. The first products based on these chips will be the Radeon X850 XT and X850 XT Platinum Edition, and we've had our grubby little hands on one of these cards long enough to benchmark it. In fact, we've benchmarked it against nearly every card we could find. Read on for a look at how ATI is remodeling the high end of its product line, and for a performance comparison of all of the latest the graphics cards from $199 and up—including dual GeForce 6800 Ultras in SLI.

ATI's new arsenal
Both of ATI's new graphics chips, the R430 and R480, are derived from the R420 graphics processor found on prior Radeon X800 cards. The R420, in turn, traces its roots to the R300 design used on the original Radeon 9700. The R430 and R480 aren't revolutionary by any means, but ATI has brought some notable changes to each of them.

The R480 will be aimed at the very top of the performance ranks. Like the R420, the R480 is manufactured by TSMC on its low-k 130nm fab process, but the R480 and its supporting cast have been tweaked and tuned to reach higher clock speeds more easily and reliably. For the R480 chip itself, the big change is in power management. ATI has endowed the R480 with a dynamic clock gating capability, a la the Pentium M, that allows the chip to deactivate parts of itself when they're not being used. ATI says the R480 should use as little as half the power and produce half the heat of the R420 in "2D" desktop use.

The R480's supporting cast gets similar tweaks. ATI has chosen a different chip substrate component in order to ease the quest for higher memory clock speeds. The board design has been changed to improve power delivery to the graphics chip. And, most prominently, cards based on the R480 will have a Dustbuster-esque, dual-slot cooler strapped to the side, much like NVIDIA's top-end cards. Check it out:


The Radeon X850 XT Platinum Edition

Before you snort your coffee through your nose, rest assured that the Radeon X850 XT does not sound like a Dustbuster—or a GeForce 5800 Ultra, for that matter—in normal use. I have to admit, I was part bemused and part terrified when I first fired up a system with a Radeon X850 XT PE card in it. At boot time, that blower cranked up briefly to full speed, aurally evoking an Oreck XL. Once those few seconds passed, though, the blower never did get back up to that speed again, no matter what I did with the card. In intense 3D gaming and benchmarking sessions, even with relatively warm ambient temperatures, the X850 XT PE was generally quieter than a GeForce 6800 Ultra, which isn't bad company to keep.

Still, the other shoe has dropped. ATI has gone to a dual-slot cooler in order to keep pace with NVIDIA's uber-high-end cards. This change, like all the others to the R480, is intended to bring higher clock speeds with less fuss, so that supply of R480-based cards might actually be able to keep up with demand.

The second prong of ATI's new high-end assault is the R430. Like the R420 and R480, the R430 has 16 pixel pipelines and six vertex shader engines. Instead of dynamic clock gating and a big-ass fan, though, the R430 gets a bit of a die shrink courtesy of TSMC's 110nm fab process. This process, combined with lower clock speeds, should allow R430-based cards to thrive with a relatively minimalist single-slot cooler.


R430-based Radeon X800 cards will get a much smaller cooler

As you might have guessed, the R430's mission in life will be a little more modest, performance-wise, than the R480's. Here's a brief overview of how ATI will be using these new chips in actual products.

 Chip Core clock (MHz) Pixel pipelines Memory clock (MHz)Memory onboardDisplay outputsMSRP
Radeon X800R43040012700128MBVGA+DVI+TVo$249
Radeon X800 XLR430400161000256MBVGA+DVI+TVo$349
Radeon X850 ProR480520121120256MBVGA+DVI+TVo$399
Radeon X850 XTR480520161120256MBDVI+DVI+ViVo$499
Radeon X850 XT Platinum EditionR480540161180256MBDVI+DVI+ViVo$549
  • The Radeon X800 is based on the R430 chip, but it will only have 12 pipelines enabled. ATI had once planned to sell a version of the Radeon X700 XT with 256MB of memory onboard for $249, but they now say that won't happen. Instead, we'll get a higher-performance chip and less memory at the $249 price point, just below the current pricing of the GeForce 6800 128MB cards.

  • Also based on the R430, the Radeon X800 XL could be a heckuva value for the money when it arrives, but I don't think ATI will make the Christmas shopping season with R430-derived products. If they do, it'll be very close. They're telling us that we should get press samples in about two weeks. If the cards start shipping in volume by then, it just might be possible to pick one up at an online reseller in time for Christmas. Maybe. But I really doubt it.

    Both of the Radeon X800 cards will use a single-slot cooler and require no external power plug (at least on PCI Express versions).

  • The Radeon X850 Pro is a single-slot card with 12 pipelines. This one is apparently a place for ATI to direct its not-quite-right R480 chips with one of the pipeline "quads" disabled. The clock speeds on this chip are still tentative, and ATI says it won't arrive until late December at the earliest, or possibly in 2005. This card won't likely be a popular choice, because it has a higher list price than the Radeon X800 XL but should perform about the same.

  • The R480-based Radeon X850 XT is slated for arrival in mid-December. X850 XT boards will not be produced by ATI, only by its board manufacturing partners. This product essentially replicates the specs and performance of the ever-so-scarce Radeon X800 XT Platinum Edition, with a few exceptions. Yes, it carries with it a dual-slot cooler, but it comes with dual DVI outputs for driving a pair of LCD monitors without the analog conversions muddling things up. (Not all X850 XT cards will necessarily have dual DVI ports, but at least some should.) We've hassled ATI in the past about the lack of a second DVI output on a $500 graphics card, and we're pleased to see that they've responded.

  • ATI's new king-of-the-hill product is the Radeon X850 XT Platinum Edition. The ATI-branded version of this puppy is supposed to be available at online resellers today, right as the product launches. Retail availability of the X850 XT PE will lag behind "e-tail," as it likely will for all of these products. For $50 more than the X850 XT, the Platinum Edition offers a teeny bit more performance and a little bit of prestige.

  • Ye olde Radeon X800 Pro will persist as an R420-based product at $299, mostly for PC makers who have qualified the product and don't want to change horses in mid-stream. The Radeon X800 XT and X800 XT Platinum Edition will be put out to pasture. ATI says the Radeon X700 series will continue to move down in price over time.
All of the cards being announced today are PCI Express models. The word is that AGP equivalents are coming shortly, but ATI hasn't announced anything yet and hasn't given a firm timetable for their release. We asked about whether the new AGP cards will use a PCI Express-to-AGP bridge chip, like NVIDIA's GeForce 6600 GT AGP, but ATI wouldn't confirm that.