Nvidia’s GTX680 uses a system of ‘dynamic’ overclocking, otherwise known as ‘Boost clocks’.
This Boost clock mode uses a variety of factors to determine whether it is a good idea to run at higher speeds, or not as the case may be. It analyses power consumption, GPU load, temperature and memory load, among other factors.
The driver is coded to make on the fly decisions about what clock speed is safe in comparison with heat output and power use. The automatic overclocking algorithms need to be coded with a variety of safety parameters.
Above, the GPUz screenshot of the Asus GTX680. We can see that the boost speed is set to 1,059mhz. This is the ‘average’ clock speed that the core will run under during typical gaming load. The clock speed may actually exceed this speed depending on the given situation.
For overclocking today we used the latest beta of MSI’s Afterburner software. We spent a long time playing with the card and analysing how far we could push it without encountering instability. I will say now that we managed to get the card higher than the speeds below, but I did notice very minor artifacting with some games, which would indicate potential problems, long term.
The latest Afterburner works on a “+” figure, indicating speeds above the default clocks. The card has a huge level of headroom available, stable at 1,204mhz core with the memory running at a staggering 7Gbps effective (1756/7,024mhz). We didn’t play with voltage tweaking as the card runs at just under 90c with our final settings above.
Incredible results, scoring over 10,000 points. The final score of 10,458 points is around 500 points more than the last generation HD6990. It is only around 1,500 points less than two GTX 580′s in SLi!