Power Consumption

To test for power consumption we use the included iPower Meter found with our Thortech PSU. As system load figures obviously differ from idle it is extremely difficult to get an accurate figure of system draw and then simply take this figure away from the overall amount because each game will generate varying levels of CPU and hard drive activity. Dynamic power adjustments which fluctuate in game will also affect accurate power figures thus rendering any such power consumption calculations redundant at worst and approximate at best.

We will therefore take our system readings averaged over a benchmark run of Tessmark (100% load) and after 20 minutes of being idle in Windows 7. These can then be used as a comparison to other graphics cards to determine how much more or less power you can expect a GPU to consume.



The HIS HD7790 Turbo consumed by far the least power. Under full load it pulled just 192W so I would expect the card to pull slightly less under 'normal' gaming scenarios as Tessmark stresses a card thus drawing more power than a game ever would.

Temperature

To test temperatures we measured idle temperatures after booting windows, letting all applications finish loading and ran a few benchmarks. Once the benchmarks were complete we left the card to reach a cooling plateau where we then took the idle temperatures. For the load tests, we would normally run Furmark for 20 minutes, taking the absolute maximum temperature attained however we found that this throttled the card and resulted in spurious results. So we set Heaven running continuously for 20 minutes and used this as a temperature result as the card did not throttle with this application.



Surprisingly, the HIS HD7790 was the hottest card on test. In fairness 63c is hardly anything to worry about and will neither hold back overclocking nor cause any damage to the card. When you consider that high end cards draw 80c+, 63c is very cool by comparison.

Acoustics

The card was neither loud nor quiet. In idle conditions it was barely noticeable and only became ever so slightly 'whiny' after an hour looping Unigine's Heaven 4.0 during our overclocking stability tests.