Board analysis

When NVIDIA first launched their GeForce FX cards for the PCI Express platform, GeForce PCX, ATI was quick to proclaim that they were the first video card manufacturer to offer native PCI Express parts with their X300 and X600. For months both sides argued over whose strategy was best. The situation was exacerbated by the fact that PCI Express products (both system chipsets and graphics cards) performed similarly to their AGP-based counterparts.

NVIDIA scored a big win however when they announced the GeForce 6600 GT AGP. Their HSI chip allowed them to bring a high performance card to the $200 AGP market months before ATI, who were only able to counter by lowering the price on the RADEON 9800 PRO to $200. Without bridging technology of their own, they had no other choice.

RADEON X850 XT Platinum Edition AGP

Back of the card

Fortunately for ATI, this is no longer the case. Their Rialto bridging technology converts PCI Express signals to AGP, just like NVIDIA’s HSI, only Rialto boasts one key feature, it does all this passively. NVIDIA’s HSI chip generates a considerable amount of heat, requiring a large aluminum heatsink for proper cooling.

Rialto bridge chip

Another shot of the bridge chip

ATI’s AGP-based RADEON X850 XT Platinum Edition is a little different than the others though, as it’s a native AGP solution. Unlike ATI’s 0.11-micron parts, RV410 (X700 series) and R430 (X800/X800 XL), ATI produces native PCI Express and AGP variants of their R480 graphics core. As a result, the board design of the RADEON X850 XT PE AGP is pretty similar to the PCI Express version:

Can you spot the differences between the two cards?

Different power connectors

As you can see in the pictures above, both boards look nearly identical. Power circuitry on both is almost the same, with the AGP card requiring a few more capacitors than the PCI Express board. Of course, you’ll also notice the Molex power connector used on the AGP X850 XT PE card. ATI also uses the same two-slot cooler to keep the graphics core cool on both cards.

Fan on the X850 XT PE AGP

Copper cooling

Unfortunately, one feature that doesn’t make its way to the AGP variant of the X850 XT Platinum Edition is dual DVI. Apparently for whatever reason ATI has decided to leave this feature exclusively for PCI Express cards. VIVO however is still present. ATI also ships the board with component video cables (for HDTV users) and a VIVO cable.