PowerColor DEVIL13 HD7990 Video Card Review

PowerColor has beaten AMD to the punch with its own creation of a dual-GPU Radeon HD 7970 CrossFireX solution in a single video card package. We evaluate this awe inspiring video card and of course overclock it to its highest potential. We put it up against the best GTX 680 SLI solution also overclocked, all with the latest drivers.

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Battlefield 3

We are using the downloaded version of Battlefield 3 via Origin. This game supports two different antialiasing methods, traditional MSAA via the "Deferred AA" option and shader based FXAA via the "Post AA" option. We evaluate the highest playable gameplay settings and take into account performance and image quality, striving for the best. In that regard, we will use whatever the appropriate AA setting, or combination of AA settings, are best for the video cards being used. Our testing procedure and evaluation of graphics features in BF3 are explained in our Battlefield 3 Gameplay Performance and IQ evaluation. We are using the latest patch for this game.


Highest Playable Settings

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Starting off with Battlefield 3 Single Player we had no issues running this game well at 5760x1200 resolution. We first tried the highest level of 4X MSAA but found this to be unplayable on all video cards. We then backed down to 2X MSAA, and found that the performance was right on target and the game felt smooth. With the PowerColor DEVIL13 HD7990 we achieved an average of 58.5 FPS at 2X MSAA at 5760x1200. Our minimum framerate hit 30, but it wasn't sustained. Most importantly, the game felt smooth, it was not laggy or choppy.

Now, when you look at the "Turbo" mode performance, you will notice it is slightly under the performance of the "Default" clock speeds. In fact even the minimum framerate dips below that of the default frequencies. You would think that with a faster GPU clock frequency (1000MHz vs. 925MHz) performance would be at least a few percent higher. There is a reason why the performance actually decreases.

You will see that the "Turbo" performance line (the blue line on the graph) drops well below the other cards three times. What is actually happening is that PowerTune is kicking in, and throttling performance because at 1GHz with higher voltages, it is exceeding PowerTune's limits at default settings. We've seen this exact same problem in the past with another video card. What ended up happening there, was that we had to manually up the power slider on PowerTuner to +20 to benefit from the higher clock speeds of that video card. Later, a BIOS was released for that video card that fixed the issue. Well, it looks like we've run into that very issue again with another video card. The power demands of the DEVIL13 are so high, that in "Turbo" mode it is pushing the limits of PowerTune and that value needs to be changed in order to benefit from the higher clock speed.

Compared to the GeForce GTX 680 GC SLI setup we are seeing very close performance, the average framerate is close. However, interestingly the minimum framerate is a lot better with GTX 680 GC SLI. All in all, the gameplay experience was exactly the same between all three setups.


Apples-to-Apples

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For the apples-to-apples test we have turned up the AA setting one notch to 4X MSAA, this is the highest possible settings in the game. The average framerate is showing exactly 50.1 for both DEVIL13 configurations. You can clearly see that PowerTune is limiting performance here, offering no advantage. Compared to the GTX 680 GC SLI the DEVIL13 is slightly faster at 4X MSAA. However, while the framerates are better, all three setups were laggy and choppy and did not have smooth gameplay.