Overclocking

To find the maximum overclock of our card we used a combination of GPUTool and our benchmarking suite.
The overclocks listed here were achieved with the default fan and voltage settings as defined in the VGA BIOS. Please note that every single sample overclocks differently, that's why our results here can only serve as a guideline for what you can expect from your card.



The overclocks of our card are 880 MHz core (15% overclock) and 1280 MHz Memory (14% overclock). It is nice to see that our card managed to surpass the HD 5870 reference clock speeds, but since the number of shaders has also been reduced in the HD 5850, there is still a little bit more clock required to reach HD 5870 performance levels. Nevertheless, these numbers are proof that if you are willing to do some manual overclocking, you could reach performance levels of the next bigger, more expensive, product.

Just like on the HIS HD 5870, the Catalyst Control Center Overdrive limits are set too low, to get the maximum out of the card.

Overclocked Performance

Using these clock frequencies we ran a quick test of Call of Duty 4 to evaluate the gains from overclocking.


The actual 3D performance gained from overclocking is 12.8%.

Temperatures

Temperatures are amazing, but I would have liked it more if HIS had gone for higher temperatures and less fan noise.

Clock Profiles

Modern graphics cards have several clock profiles that are selected to balance power draw and performance requirements.
The following table lists the clock settings for major performance scenarios and the GPU voltage that we measured. We measure on the pins of a coil or capacitor near the GPU voltage regulator.


AMD includes their own overclocking utility with Catalyst Control Center. While easy to use, it also limits the maximum overclock to a predefined limit in the BIOS. This limit may vary from vendor to vendor or product to product. Following are the upwards limits for overclocking CCC gives you.