It’s been a long while since we’ve last seen a $700 graphics card, but AMD revives that tradition with its Radeon HD 6990 dual-GPU offering. Fortunately, the card has proven that its high price-tag is well-earned, as it storms past every other single and dual-GPU graphics card on the market, and introduces other useful features to boot.
To test our graphics cards for both temperatures and power consumption, we utilize OCCT for the stress-testing, GPU-Z for the temperature monitoring, and a Kill-a-Watt for power monitoring. The Kill-a-Watt is plugged into its own socket, with only the PC connect to it.
As per our guidelines when benchmarking with Windows, when the room temperature is stable (and reasonable), the test machine is boot up and left to sit at the desktop until things are completely idle. Because we are running such a highly optimized PC, this normally takes one or two minutes. Once things are good to go, the idle wattage is noted, GPU-Z is started up to begin monitoring card temperatures, and OCCT is set up to begin stress-testing.
To push the cards we test to their absolute limit, we use OCCT in full-screen 2560×1600 mode, and allow it to run for 15 minutes, which includes a one minute lull at the start, and a four minute lull at the end. After about 5 minutes, we begin to monitor our Kill-a-Watt to record the max wattage.
In the case of dual-GPU configurations, we measure the temperature of the top graphics card, as in our tests, it’s usually the one to get the hottest. This could depend on GPU cooler design, however.
Note: Due to power-related changes NVIDIA made with the GTX 580 & GTX 570, we couldn’t run OCCT on that GPU. Rather, we had to use a run of the less-strenuous Heaven benchmark.
We’ve seen our CrossFireX HD 6970 configuration out-perform the single HD 6990 in most every test, but when it comes to testing outside of performance, other benefits of AMD’s latest card can begin to be seen. While in CrossFireX mode, the top HD 6970 in our test machine reached a rather high 92°C, while the HD 6990 peaked at 85°C while pre-OCed, and 80°C at stock. Hardly a major drop, but certainly a welcome one. What about power consumption?
In comparing the Radeon HD 6990 to the CrossFireX HD 6970 configuration, improvements can once again be seen. On the pre-OC setting, which is most comparable to that CrossFireX configuration, about 47W are dropped at load, and 16W at idle. Again, not major drops, but quite significant when we’re dealing with 500W+ configurations.