Noise
The final part of the jigsaw is now in place. The Accelero Xtreme 7970 is marginally quieter when idling but much, much quieter when gaming at the stock speeds and voltage settings of the HD 7970 GPU.
Checking the logs shows the three fans of the Accelero Xtreme 7970 spin at 20 per cent of maximum in both idle and under-load modes. The very slight increase in noise is from other part(s) of the system. Meanwhile, the reference card's fan jumps from 20 per cent to 45 per cent by the end of the in-game Shogun 2 test.
Tying it together, do recall that the Accelero Xtreme 7970's GPU temps are 63°C in this case, whereas the reference's are 79°C.
Extra frequency and voltage ensures that the Accelero Xtreme 7970's fans have to spin faster to keep everything ticking along. They increase from 20 per cent (idle) to 33 per cent, while the reference's jumps to 54 per cent.
Lastly, going full out on the Accelero Xtreme 7970 is still quieter than the reference card operating at default speeds.
To the limit
The last test involves overclocking the card to the highest stable speeds with the 1.25V used in these last series of tests. We managed a final, overclocked speed of 1,150MHz core and 6,150MHz memory on the reference card and 1,180MHz core and 6,200MHz memory with the Xtreme 7970, with both cards' fan-speeds left to PWM-control.
