Temperatures And Fan Speed
Temperatures under Load (Bitmining)
Sapphire's Toxic HD 7970 GHz Edition 6 GB stays cooler with Lethal Boost enabled than it does at its factory clock rate. This is due to a more aggressive fan profile that’s activated alongside the high frequencies.
The 60-percent duty cycle at 1100 MHz is still within reason, though noise is already creeping up to an uncomfortable level. Lethal Boost triggers a jump to 73-percent duty cycle, and the static 1201 MHz sees us approach 78 percent.
We have a video of what that sounds like on the next page. But before we recorded it, we already knew that the noise level exceeded an unacceptable 60 dB(A).
Sapphire's Toxic HD 7970 GHz Edition 6 GB ran hotter than the other two profiles in our gaming workload, though it was still acceptable.
The higher clock rates are fairly similar, simultaneously offering lower temperatures and a more aggressive cooling profile.
Based on the thermals, acoustics fall right about where we'd expect them. The card's fans are noticeable, but not distracting, at 1100 MHz. The faster clock rates push the fans to an almost-70-percent duty cycle, yielding a noise level that's loud enough to hear even with headphones on.
The noise level videos on the next page provide a better sense of what our results mean in practice. We can already say that activating Lethal Boost creates quite a bit of noise.