Overclocking
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 950 MHz core (16% overclock) and 1160 MHz Memory (5% overclock). Those clock frequencies are pretty much spot on for what I'd expect for any typical HD 6850 card.
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 11.2%.
Temperatures
Temperatures are in a perfectly safe range. Personally I would have preferred a higher idle temp but less noise from the cooler. Also there seems a bit of extra headroom left in the "load" temperature.
Voltage Tuning
PowerColor's voltage regulator does not offer voltage control via I2C, so we could not test voltage tuning. Extremely motivated overclockers could still do a soldering voltmod, but that would void the warranty.
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.
| Core Clock | Memory Clock | GPU Voltage (measured) |
---|
Desktop | 100 MHz | 150 MHz | 0.97 V |
---|
Blu-ray Playback | 300 MHz | 1100 MHz | 1.15 V |
---|
3D Load | 820 MHz | 1100 MHz | 1.17 V |
---|
CCC Overdrive Limits |
---|
Core | 1000 MHz |
Memory | 1250 MHz |