Overclocking, Power, Temperatures, Fan Noise
Power consumption is not really as important on high-end consumer graphics cards as more users are comfortable with using up lots of juice to get their gaming experience where they want it to be. Still, looking at the relative power consumption of the GPUs presents interesting information on how the parts compare in terms of compute efficiency.
As promised, the Radeon HD 7970 card uses much less power than previous designs when at idle. Keep in mind, in this graph, we are not reporting the power of the ZeroCore Technology state. Based on my tests, with the screen powered down, the system with the HD 7970 drew 76.9 watts – 11 watts less! Pretty impressive for those of you concerned with heat and noise while you aren’t gaming.
The load power consumption was also very solid for AMD’s new architecture as we don’t see it using much more power than the Cayman-based Radeon HD 6970. And even though the performance lead was steadily in AMD’s favor, the HD 7970 uses 36 watts less than the NVIDIA GTX 580 and A LOT less than EVGA’s GeForce GTX 560 Ti 2Win.
For both our temperature and sound level testing keep in mind this important factor – we are testing reference designs only. Or in the case of the EVGA 2Win card, the only design. When retail cards hit the streets with custom coolers and PCB we should expect all of this to change. However, assuming many of our readers are going to be buying the first reference-based solutions, it’s worth analyzing.
The new 28nm process is showing its strength again here by allowing the higher performing GPU to run at a lower temperature than even the Cayman part. Running under a full load at 76C is pretty good but I would still expect to see the custom coolers from companies like MSI to improve on that greatly.
Our sound level testing was used with the methods we showed on the testing configuration page and shows some interesting results. Despite AMD telling us that the cooler on the new HD 7970 was improved over the previous one for acoustics, our testing showed it to be a bit louder than both the HD 6970 and the GTX 580 under a full load. At idle though, the fan on the HD 7970 was quietest however. The dual-fans on the GTX 560 Ti 2Win card took the unwelcomed claim of being the loudest.
Quick Overclocking Test
I didn’t spend a ton of time playing around with overclocking on the Radeon HD 7970 3GB but I was able get the GPU running at 1025 MHz, a solid 10% higher than the stock 925 MHz setting.
The performance results scaled as you would expect them to, as I saw anything from an 7-9% gain in instances that were GPU bound.
We will be looking at overclocking more in the future as we get in retail samples from AMD’s partners.