Heaven benchmarks my 7870.

PowerTune is probably throttling you at 1200-1300 and your chosen VDDC.

In the slider’s default position (in CCC), the coprocessor that governs AMD PowerTune will intelligently manage the GPU’s core clockspeed based on the default thermal profile of the product; a hypothetical enthusiast product might be 225W.

From there, AMD PowerTune is essentially biased towards maintaining the clockspeed defined by the user or vBIOS, whichever is higher. This is driven by the AMD PowerTune logic, which forecasts the GPU’s future temperature based on the past few microseconds of activity.

Now that you know that, it’s easier to understand how PowerTune and its CCC slider work. By decreasing the slider into the negative range, the user can effectively tell the AMD PowerTune logic to simulate a board with a TDP that’s up to 20% lower. This could be good for HTPCs or power-constrained SFF systems with smaller PSUs. In contrast, increasing the slider can effectively raise the board’s TDP by 20% of the baseline.

If a user attempts to run an application that pushes the GPU to exceed the current TDP threshold, the board may throttle the clockspeed, which would cause a dip in performance. With this in mind, overclockers should make sure to increase the AMD PowerTune slider to accommodate the new thermal load introduced by a higher GPU clockspeed.

In short: it's about designing a GPU that ships from the factory with a higher reference clockspeed.

Prior to the advent of PowerTune, we set the GPU clockspeed based on the market's most intense applications, which recently has been Furmark and the AvP benchmark. We'd run those applications at full throttle and increase the clockspeed until we hit the desired board TDP, and then that would be your final clockspeed. Maybe it was only 600MHz to achieve, as an example, 250W.

The problem with that scenario is that it's completely unrealistic. Nobody buys a GPU to play furmark, and nothing but Furmark/AvP produces that kind of GPU load. So why would you ever let unrealistic applications have that level of control?

So now we have PowerTune, which allows us to use a different set of applications to determine the shipping frequency of the board. It lets us use real games as the baseline, rather than synthetic BS that doesn't represent the real world in any way, shape or form. Real games can have a higher clockspeed, and more real performance because of this system.

Even so, when users really push their overclocks and voltage, PowerTune can still step in to bring the board back to a safe zone so it isn't destroyed.

Thracks,
does PowerTune mean that it is safe to push 1.3v 24/7 on my 7870, presuming temps are OK? I've be afraid to do so up until now because I don't want to break anything!

Also, you don't happen to know the max safe temperature for the 7870, do you? I've been trying to keep the card under 75*c, though I am worried that even this is too much heat.

Cheers,
Warweo.