Radeon X850 Platinum Edition Review

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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.