ATI Graphics Card Buyer's Guide 2006, Part II

Sapphire Radeon X1900 XTX - Overclocking And Heat

The default clock speeds are given as 500/594 MHz (GPU/memory) in the driver's information center. The overclocking presets in the Overdrive tab of the driver read out as 648/774 MHz. All of our X1900 XTX samples came with this combination of frequencies preset in the Overdrive section.

Before you can overclock the card, you must run the automated clock configuration utility, which takes a few minutes. Accepting the speeds suggested by the utility automatically selects them. The Sapphire card reached a maximum clock speed combination of 689/797 MHz; this is marginally lower than what the Gecube and Powercolor samples were capable of, as tested in Part 1. Overclocking the card increases its overall performance by 2 percent. The memory frequency displayed in the screenshot refers to the physical clock speed. Since this is DDR memory, the clock speeds are doubled in the technical specifications.

This chip is a hot piece of hardware indeed. While it idles at a moderate 54°C in 2D mode, it reaches up to 94°C under extended 3D load. The chip is able to deal with this heat, with the cooler doing its part very audibly.