Sapphire HD 7970 OC Edition Video Card Review

The Sapphire HD 7970 OC Edition video card has arrived and brings promise of low temperatures with Sapphires Dual-X Cooling System. It also features a Dual BIOS with both a passive and more aggressive profile. Will Sapphires highest end HD 7970 be able to keep up and compete with NVIDIA's flagship GeForce GTX 680?


Power Consumption

We tested the power utilization at the wall of the entire system without a video card, and with each video card at idle and full load. For full load power and temperature testing we used real gaming and recorded the highest value in each game. To measure power consumption we use a P3 International Kill-A-Watt device to measure power consumption from the wall. The entire testing system, excluding the speakers and monitor, are plugged into the Kill-A-Watt device. Therefore, power consumption numbers include all components, not just the video card. For this process, we played through the entire testing level while watching the Kill-A-Watt, and then recorded the highest number we saw during the test.

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As you have seen in our gameplay and performance testing so far a stock Radeon HD 7970 and a stock NVIDIA GeForce GTX 680 are very identical in performance. With performance being so close it is important to see the power consumption for each video card. The reason we are reporting all five tested video games is because the NVIDIA GeForce GTX 680's clock speed changes depending on the GPU load.

Without a video card installed, our test system pulled 160 Watts from the wall when idling at the desktop. After we installed the Sapphire HD 7970 OC Edition power consumption at Idle increased to 179W. The overclocked Sapphire HD 7970 OC Edition required just 2W more at 181W. Our reference Radeon HD 7970 idling at the desktop drew 190W and the NVIDIA GeForce GTX 680 drew 178W.

The Sapphire HD 7970 OC Edition had the highest power consumption under load in Battlefield 3 at 472W. This is 16W less than the reference Radeon HD 7970's highest power draw under load which was also in BF3. The NVIDIA GeForce GTX 680's highest power consumption was in Deus Ex where it drew 461W. Under full load the Overclocked Sapphire HD 7970 OC Edition's highest power consumption was 562 Watts in Battlefield 3.

The Sapphire video card out-of-the-box is clearly more power efficient than a standard reference Radeon HD 7970. Sapphire has improved on power efficiency, even though it is running at higher clock speeds.

Temperature Measurement

To measure temperatures on these video cards we used the sensor information from GPU-Z to find the GPU’s highest temperature during the test run. We found that Battlefield 3 provided the highest temperatures from the games used in this evaluation. To get our numbers for the process we played through an entire test run with GPU-Z recording temperature sensor information in the background. We then selected the highest temperature it reported.

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When Idle at the desktop the Sapphire HD 7970 OC Edition's temperature was 27c with fans at 20%. The Overclocked Sapphire HD 7970 OC Edition was only 2 degrees warmer at 29c with fans at 22%. The reference Radeon HD 7970 which has only one fan was 42 degrees Celsius at Idle with fans at 24%. The NVIDIA GeForce GTX 680 was also over 10 degrees Celsius warmer than both of the Sapphire HD 7970 OC Edition video cards at 40c with fans at 22%.

Under full load the temperature on the reference Radeon HD 7970 increased from 42c to 79c with fan speed increasing to 58%. The NVIDIA GeForce GTX 680's temperature under load increased from 40c up to 81c with fans at 54%. The Out-of-Box Sapphire HD 7970 OC Edition's temperature increased from 27c to 56c under load with fan speeds only getting up to 46%. The fully overclocked Sapphire HD 7970 OC Edition under full load had a temperature of 68c with fan speeds forced to 70%.

The Dual-X cooling system that Sapphire outfitted the Sapphire HD 7970 OC Edition video card with did a wonderful job through our gameplay testing by keeping the video card cool while remaining quiet. The fans became noticeable over 60% and were distinguishable over normal operating noises above 65%. Still, at 70% the noise was not unbearable. The noise level at 70% was comparable to the reference Radeon HD 7970's fan at 55%, but provided much better cooling results. The Dual-X cooling system allowed us to achieve a high overclock and enjoyable gameplay in every game.