In Video: Noise And Fan Speed Results
We chose several fixed fan speeds to benchmark the Radeon HD 7970 Super Overclock's fan noise. For each speed setting, we recorded both video and audio from a distance of 50 cm; this is the same distance we used to measure noise level. The audio was recorded by the same equipment used to measure noise level, and then added to the video track after recording was complete.
|Header Cell - Column 0||Test System|
|Processor||Core i7-2600K (Sandy Bridge), 32 nm, 8 MB Shared L3 Cache, Overclocked to 4.5 GHz|
|Cooler||Prolimetech Supermega + Noiseblocker Multiframe|
|Memory||4 x 4 GB Kingston HyperX DDR3-1600|
|Mother Board||Gigabyte Z68X-UD7-B3|
|Operating System and Driver||Windows 7 Ultimate x64 Catalyst 12.6 WHQL|
|Test Software||FurMark, OCCT|
30% Fan Speed
We used a 30% fan speed as our starting point for testing Gigabyte's Radeon HD 7970 Super Overclock at idle (with an ambient temperature of 28 degrees Celsius).
The factory-set 40% duty cycle is overkill when the card isn't doing anything. At 30%, its noise level isn’t as bad as we thought it might be. The five fans do generate a metallic whirring noise, which isn’t pleasant.
Since the card is designed to push the warm air through an opening in the side of a case, you can't count on insulation material to help deaden the Super Overclock board's acoustic output. Consequently, any proud owner of this card will just have to live with the noise. At 30% fan speed, we’re looking at under 36 dB(A); 40% takes this up to 38 dB(A).
50% Fan Speed
We saw fan speeds between 45% and 55% in our gaming benchmarks and stress tests. Most games let us hover under 50%, while compute-based apps took us over 50%. This resulted in measurements of up to 45 dB(A) in games and 47 dB(A) in GPGPU applications.
Both numbers are acceptable, even though models with radial fans like Asus' 7970 DirectCU II make a lot less noise. The Asus card drives up ambient temperatures inside your case, though, whereas Gigabyte's Radeon HD 7970 Super Overclock actually manages to facilitate case cooling.
We went so far as to compare the temperature of our CPU in a system armed with the Super Overclock card and a Radeon HD 6570 after several hours of use, and didn't see any difference between the measurements.
75% Fan Speed
At 75% duty cycle, five small fans generate 60 dB(A), which is about what the reference Radeon HD 7970 GHz Edition demonstrated in our FurMark benchmarks. The GPU temperature maxes out at 65 degrees Celsius with the case closed and 68 degrees Celsius with it open in our stress test, compared to the reference Radeon HD 7970 GHz Edition’s 90 degrees Celsius.
After looking at those thermal results, we decided to use a custom fan speed profile. The temperature headroom simply isn't worth the obnoxious noise level.
This is very similar to what happened when we benchmarked Gigabyte's GeForce GTX 680 with Windforce 3X cooling. Gigabyte ended up changing its fan speed profile in the card’s BIOS after consulting with us.
100% Fan Speed
The only way to push the fan to 100% is to dial it in manually. The noise level reaches a jet engine-like 62.9 dB(A), which is far above what anyone should even consider listening to on a regular basis. Then again, under normal use, nobody will have to. We included it just to give a reference for the maximum possible noise level.
Gigabyte's Radeon HD 7970 Super Overclock with Windforce 5X cooling is quieter than we expected. Its noise level isn't bad at idle, and it's acceptable under load, measuring less than 50 dB(A) at fan speeds of around 50%. We’ll try to optimize the noise level even further by using the card’s cooling reserves with our custom fan speed profile.