HIS Radeon X1800 XL - Overclocking And Heat

The default clock speeds are given as 500/495 MHz (GPU/memory) in the driver's information center. The same speeds are also suggested as the overclocking presets in the driver's Overdrive tab. In order to overclock the card, the automated clock configuration utility must be run first, which takes a few minutes. Accepting the speeds suggested by the utility automatically selects them. The HIS card can be overclocked to a maximum frequency of 554/549 MHz. By way of comparison, Sapphire's X1800 XL reached a GPU frequency of 579 MHz. Overclocking the card increases its overall performance by 3.5 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.

The card gets hot, idling at 59°C in 2D mode. Under extended 3D load, the fan stabilizes the chip's temperature at around 70°C, albeit quite audibly.