Page 12 - Power Usage, Temperature, Noise
As a base reference, I have included a measurement for the entire system without the graphics card installed. Please note that the load conditions cannot be directly compared against this base value, since the entire system is under load, and as such the CPU will also contribute to the increased power usage. With that in mind, the Gigabyte Radeon HD 7870 2GB OC's power consumption reached a maximum of 248W load from 61W idle -- a difference of 187W. Gigabyte likes to promote their lower RDS(on) MOSFETs, quality solid capacitors, and low power loss ferrite core design. In the past, I have seen a difference in power consumption as much as 10W against reference cards with regular components. The above results were obtained when running Furmark's stress test, and your graphics card is not likely to see any higher loads -- especially under normal usage. To be honest, you are not going to get anywhere near this under intense gaming sessions, so really -- this is just for interest's sake, haha.
For the purpose of this review, I left the fan on default settings, so its speed is allowed to vary accordingly with temperature. I also wanted to see what the card is capable of doing inside my low airflow chassis configuration. Most people should get better results in real life than our hot running test bench environment. With that in mind, I left the stock paste intact for testing before taking it apart for the photo session on Page 3. Its thermal interface material was applied properly from the factory, and I have noticed little performance difference between what Gigabyte has included with the card and my Arctic Cooling MX-2 paste applied afterwards. Secondly, even under our intense Furmark load tests, the Gigabyte Radeon HD 7870 2GB OC peaked out at only 61c; a figure that is simply amazing. It is important to point out this is the worst case scenario -- you will not hit this temperature under normal gaming sessions. Most cases should have better airflow than my configuration anyway.
As far as noise is concerned, while this is very subjective, I am quite a picky person on noise, and the loudest component in my entire system is probably my Noctua ultra low noise fans -- and they are not loud at all. You can see my test configuration on the third page of this review. In my opinion, there is no objective measurement of noise, as measuring sound pressure level is often impractical, because human ears are more sensitive to some frequencies than others. On a scale from 0-10 where 0 is silent and 10 is the loudest, I would rate the Gigabyte Radeon HD 7870 2GB OC to be at 3.5/10 at 40% fan speed. 40% is the default fan speed. The fan will kick up to 60% at full load, unless set otherwise. On a scale from 0-10, where 0 is silent and 10 is the loudest, I would rate the Gigabyte Radeon HD 7870 2GB OC to be at 4.5/10 at 100% fan speed. It is definitely audible, but it is not necessarily loud, and the fans are relatively smooth running at high speed. If you want your card to be appropriate in a quiet PC configuration, keep the fan running at or below 30%. Once you bump it past that magic mark, you are going to hear it.