Power Consumption, Temperature, Noise and Overclocking
Since we got our hands on a brand new graphics card, we have taken the liberty of checking out Radeon HD 6990 power consumption. So, we performed a series of corresponding tests using our standard platform:
- Intel Core 2 Quad Q6600 CPU (3GHz, 1333 MHz FSB x 9, LGA775)
- DFI LANParty UT ICFX3200-T2R/G mainboard (ATI CrossFire Xpress 3200 chipset)
- PC2-1066 SDRAM (2x2 GB, 1066MHz)
- Enermax Liberty ELT620AWT PSU (620W)
- Microsoft Windows 7 Ultimate 7 64-bit
- CyberLink PowerDVD 9 Ultra/"Serenity" BD (1080p VC-1, 20 Mbit)
- Crysis Warhead
- OCCT Perestroika 3.1.0
The testbed for measuring electric characteristics of graphics cards uses a card designed by one of our engineers, Oleg Artamonov, and described in his article called PC Power Consumption: How Many Watts Do We Need?. As usual, we used the following benchmarks to load the graphics accelerators:
- CyberLink PowerDVD 9: FullScreen, hardware acceleration enabled
- Crysis Warhead: 1600x1200, FSAA 4x, DirectX 10/Enthusiast, "frost" map
- OCCT Perestroika GPU: 1600x1200, FullScreen, Shader Complexity 8
Except for the maximum load simulation with OCCT, we measured power consumption in each mode for 60 seconds. We limit the run time of OCCT: GPU to 10 seconds to avoid overloading the graphics card's power circuitry. Here are the obtained results:
The initial concerns have been confirmed. AMD Radeon HD 6990 has truly monstrous power appetites. In fact, onboard diagnostics algorithms instantly put our sample in a halt mode as soon as we started OCCT: GPU test. This particular test puts an abnormal amount of load on some power and chip components inside the card so it is only natural that engineers would like to protect their brainchild. For the most part of its work cycle our hero relies on only one of its PCIe 8-pin connectors for the juice. Now let us check the wattage before we draw any conclusions.
If you are a Greenpeace activist, then AMD Radeon HD 6990 is definitely not for you. It manages to lose in every aspect of the test. Idle power consumption is around 50 Watts, which is really only a fraction compared to the 395 Watt in the burn mode. But if you take a look at the competition, you will actually see that Nvidia GeForce GTX 580 needs only 26.5 Watts to process Windows 7 desktop operations. Blu-ray playback is also a scene to forget for Antilles based product as it requires an impressive 110 Watts to run in this mode, while is 40 Watts more than the rival needs. We would like to call this power hunger a serious drawback, but then again you are not going to buy a 911 turbo Porsche just because of its fuel consumption numbers.
AMD engineers and designers have really cracked it this time. Despite almost 400 Watts of heat output, our sample stayed relatively cold throughout the testing. What is even more impressive, it is the fact that thanks to a new evaporation camera radiator design idle temperature is 16°C lower in comparison to the previous attempt with the Radeon HD 5970 graphics card. A round of applause is more than befitting here.
Lots of power coupled with low operating temperatures should result in high level of noise. But every rule has an exception. With the ambient noise of 36 dBA, the noise at a 1 meter distance from our testbed with the AMD flagship offering inside was at respectable 40.2 dBA. This is a good result for a bulky power-hungry dual chip solution. Unfortunately, as soon as we launched our game mode, the noise output by Radeon HD 6990 cooling solution increased to uncomfortable 50.2 dBA. This is by no means a disaster, but the sound is easily identifiable and ever-present. Please remember to wear a headset in your online battles.
As for overclocking, we did not have much luck. Initially our sample allowed for a +60 MHz overclock on the chip, but as a few tests heated up the room and the PCB, the driver became unstable and we decided to drop the overclocking tests till we get our hands on a retail sample. At the moment there is still a lot to play with, especially considering the dual BIOS.