Overclocking

ATI's RV6xx GPUs use a new dynamic clock mechanism that dynamically selects the clock speed based on GPU load. Unlike previous cards this is done completely in hardware by the GPU without any intervention required by the driver. Our 2400 XT has three clock states: Low (110 / 252 MHz), Medium (400 / 300 MHz) and High (700 / 800 MHz). Fan speeds are adjusted by temperature. This means that the card is quiet in 2D mode or when load is low and the fan speed gets ramped up when the card gets hotter and requires additional cooling.

We used ATITool and the AMD GPU clock tool to manually search for the maximum core and memory clocks.



The final overclocks of our card are 756 MHz Core (8 % overclock) and 837 MHz Memory (4.6 % overclock). The original overclocks were somewhat higher but 3D applications kept crashing, even though ATITool said the card is error free. These overclocks are ok but not spectacular.


The temperature controlled fan does a good job at keeping the card cool. Considering the small size of the fan it should be no problem building a passively cooled 2400 XT.