All of our measurements are taken in a semi-anechoic chamber at an ambient temperature of 22° C from a distance of 50 cm (19.7 inches), with the microphone perpendicular to the middle fan of the Radeon HD 7990. As always, we report noise levels in dB(A) to account for the human ear’s idiosyncrasies as much as possible.
These tests employ the same calibrated setup used for our PC audio testing, since our studio microphone enables more precise measurements at frequencies above 8 kHz than a sound-level measuring device. Why go to all of that extra effort? Because sound pressure level doesn’t tell the whole story. Although we actually like the acoustics of the Radeon HD 7990’s triple-fan cooler a little more than GeForce GTX 690’s single-fan solution, we also have to live with the fact that, this time around, fan noise isn’t what you’re most likely to hear while you game. As mentioned earlier on, variable loads cause the card’s ceramic capacitors and PCB to vibrate, resulting in a whining sound that grates on your ears.
The company says it actually did quite a bit to minimize this, and you can further help by enabling v-sync to limit frame rates. This brings us back to our analysis and the fact that subjective impressions are a lot different than what an SPL meter would have reported. Don’t worry—we have video to make all of this clearer.
Temperatures, Fan Curves, and Sound Levels
Our first point of interest is comparing the Radeon HD 7990’s maximum temperature to GeForce GTX 690. Both cards are taxed using a GPGPU-oriented application that generates a continuous 100% load. While Nvidia’s dual-GPU board runs at a constant 914.5 MHz, unable to accelerate its core clock any higher, the Radeon HD 7990’s frequency oscillates between 950 and 1000 MHz even after ten minutes, though it tends to trend closer to the base clock rate.

As we can see, the Radeon HD 7990 runs slightly cooler. But how do those temperatures correspond to fan speed?
Unlike the GeForce GTX 690, which sports a center-mounted axial fan using large blades set at a rather sharp angle, AMD’s Radeon HD 7990 is equipped with three axial fans, each of which employing blades that are more curved and set at a shallower angle. This paves the way for lower noise levels and temperatures, even though the trio of blowers rotate faster, too.

AMD’s fan curve is less granular than Nvidia’s, though it’s also generally more conservative. The 7990’s fans spin slower at temperatures under 60°C. In theory, this could yield very low noise output at idle or when the card encounters a moderate load. That’d be quite a coup for AMD, which struggled with noise in the past, but appears to have a real winner in its Radeon HD 7990. Unfortunately, though, more taxing applications trigger the whining issue that creates more noise than the fans.

What AMD refers to as capacitor and PCB vibration ends up costing the Radeon HD 7990 its theoretical advantage. It’d be great to see AMD fix this and really redefine what it means to sell a flagship dual-GPU card that barely makes a whisper.
This takes us to our next question: How much of the noise is actually generated by the fans themselves?
- AMD's Malta Becomes The Radeon HD 7990
- Much-Improved Acoustics, With One Nagging Issue
- Test Setup, An Explanation Of FCAT, And Benchmarks
- Results: 3DMark
- Results: Battlefield 3
- Results: BioShock Infinite
- Results: Borderlands 2
- Results: Crysis 3
- Results: Far Cry 3
- Results: Hitman: Absolution
- Results: The Elder Scrolls V: Skyrim
- Results: Tomb Raider
- Radeon HD 7990 Vs. GeForce GTX 690: The Pepsi Challenge
- Noise Measurements And Fan Speed
- Noise Analysis: Frequency Spectrum And Videos
- OpenCL: General-Purpose Computing
- OpenGL: Synthetic Gaming Performance
- Can The World’s Best Bundle Save Radeon HD 7990?

If you're looking to game at 1920x1080, I can save you a ton of money by recommending something less than half as expensive. This card is for folks playing at 2560 *at least.* Next time, I'm looking to get FCAT running on a 7680x1440 array
Thats some nice gains from the prototype driver.
Power is the one thing I didn't have time for. We already know the 7990 is a 375 W card, while GTX 690 is a 300 W card, though. We also know AMD has Zero Core, which is going to shave off power at idle with one GPU shut off. I'm not expecting any surprises on power that those specs and technologies don't already insinuate.
If you're looking to game at 1920x1080, I can save you a ton of money by recommending something less than half as expensive. This card is for folks playing at 2560 *at least.* Next time, I'm looking to get FCAT running on a 7680x1440 array
People mostly buy Intel (I3/i5 a lot more than i7) just because Intel can provide top of the line CPUs in the i7 Extreme range. Same goes here, if some hears that AMD has a better 1000$ card than Nvidia, they will probably spend 100-200$ for an AMD card and not Nvidia.
Power ... unless you`re not a guy who saves 2 years in a row for this card to have a 6 months nerd gaming glory you won`t care that much how power hungry this card is.
Is just like asking Ferrari or Lamborghini how many mpg their cars do.
2. Regarding the fan noise and the hum : It would be interesting to know how much noticable is the fan noise and the hum with increaseing listner distance. IOW, which noise is more noticable at near/medium/far distances ?
Drivers still are AMD's biggest weakness. I would have expected AMD to havetop-notch , A-one drivers to go with the HD7990. After all, this is AMD's halo product. The first impression is what matters. The conclusion is basically "Card is good. Drivers are poor, with better coming in future". So ultimately its selling a promise, which may/may not succeed. It appears to me that AMD doesnt value its own products.
Also, has the Video Conversion Engine in AMD taken off ?
Unfortunately I'm really not sure the whining issue is something that can be fixed with a driver update. I think it has more to do with the hardware on the board than anything else. But it's good to see that AMD has finally recognized the frame time variance and micro-stutter problem, and are actively pursuing a solution. Although the test in the review was limited, I think it's telling that every gamer tested was able to recognize the difference between AMD and Nvidia cards, and even the difference brought by AMD's own prototype drivers.
I know and that's what I meant by hopping that they would have addressed the whining with this card. It happens to all their cards, well the ones that I have owned especially the XFX and if they knew what causes then they should have fixed it.
Let's hope that the prototype driver will also translate to better drivers for all their GPUs and address the frame rate issues. Other than that, it is a good card but I think, for my personal use since I was waiting to see what this can offer, I will just get the GTX 680 or the GTX 780 next month and will definitely go back to AMD if they address those issues.
For everyone seeking power and heat results:
http://www.anandtech.com/show/6915/amd-radeon-hd-7990-review-7990-gets-official/16
It consumes a lot of power under load, substantially more than the GTX690, but like Chris said that's to be expected. The big difference with the 7990 seems to be acoustics in relation to temps at load. It's a massive improvement over the 6990, and pretty much on par with the GTX690. Unfortunately the coil whine seems to undo a lot of the improvements made to the stock cooler, but all things considered it's pretty impressive what AMD was able to do in this area, especially in comparison to unofficial solutions from other vendors (dual slot, only requires 2 8-pin).
Sorry, that's a reading fail on my part. Thought you said, 'hope they'll address the whining' or something to that effect.
No problem.