To find the maximum overclock of our card we used a combination of GPUTool and our benchmarking suite.
The overclocks listed in this section 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 860 MHz core (8% overclock) and 1540 MHz Memory (23% overclock). While the core overclock is a bit disappointing, memory seems to be able to reach extremely high levels. Based on the 860 MHz number, my guess is that the GPU chip on our sample did not make the clock qualification for the HD 6970 (880 MHz), so it ended up on a HD 6950.
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 11.3%.
Temperatures seem to be well optimized. A little higher idle temperature for less idle fan noise would be something I'd prefer, but overall the temperature looks good.
At this time there is no way to adjust the voltage of these cards. The voltage controller itself supports I2C, so it is only a question of time until willing users can adjust their GPU voltage.
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.
|Desktop||250 MHz||150 MHz||0.90 V|
|Blu-ray Playback||500 MHz||1250 MHz||1.01 V|
|3D Load||800 MHz||1250 MHz||1.11 V|
|CCC Overdrive Limits|