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AMD Radeon HD 6990 Review

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PROS / This graphics card has an unmatched texture fill rate.

CONS / This card is loud while under heavy use, and it has compromising heat dispersion system.

 VERDICT / Overall, this is the most powerful graphics card on the market, but you may have to buy a water block to help with cooling.

Editor’s Note: This product has been removed from viewing as part of this site because it has been replaced by a new generation of graphics card. You can still read our original review below, but TopTenREVIEWS is no longer updating this product’s information.

AMD Radeon HD 6990

With the release of the AMD Radeon HD 6990, AMD continues to maintain the best graphics card title and is our TopTenREVIEWS Gold Award winner. The flagship of the 6000 series has taken graphical computing power to a completely new level. This dual GPU card allows you to process thousands of bits of information simultaneously, which ups the speed of rendering high-resolution video and graphics. With HD swiftly becoming the standard, the AMD Radeon HD 6990 and other impressive graphics cards will also become standard to meet the needs for processing it. This standard already affects the gaming world that demands more and more GPU power every year.


The power of dual cores is always impressive, and now AMD has proven twice in a row that they know how to get as much graphics processing power out of a single PCIe expansion slot as possible. Each core on the AMD Radeon HD 6990 is clocked at 830 MHz. Between the two, they have over 3,000 steam processors, which is impressive, but not the most we've seen. This graphics card takes second place when it comes to transistors as well, but it is far beyond the rest with its 5,100 GFLOPS (giga floating point operations per second) of computing capacity. In addition, the 159.4 texture fillrate is the highest you will find.

There is a flaw to this fearsome GPU duo. Up until this point graphics card manufactures were careful to not surpass the recommended TDP (thermal design power) of 300 watts. However, the AMD Radeon HD 6990 has completely smashed that rule with a TDP of 375 watts at stock settings. Unfortunately, it was necessary for AMD to do this in order to keep the graphics card cool enough. However, with great cooling power, comes not great responsibility, but great levels of noise. It is a shame that there is no way to convert that noise into energy. If there were a way, the AMD Radeon HD 6990 would be the perfect graphics card. However, you will have to rely on your speakers to be louder than this card under load, or buy a water block for it. Either one should do the trick.


The AMD Radeon HD 6990 gave each GPU that it is sporting 2GB of GDDR5 memory. The memory has an impressive clock speed of 2.5 GHz, which far outpaces all other graphics cards. The bottleneck on the memory is the bus width. AMD is still hanging on to the 256-bit standard they have had for the last couple of years. With a dual GPU system like this one, it is not as big of an issue because there are two of them, but it can still be improved. Thankfully, they more than doubled the memory bandwidth since the 5000 series cards.

Noise and Power

AMD has implemented their typical line up of technology into the AMD Radeon HD 6990. For parallel computing, their Stream and video processing uses Avivo HD. Eyefinity is still their multi-display solution, and it is still amazing with its resolution potential capping out at 7680 x 3200. Wouldn't that take 6 monitors to achieve, you ask? Yes, but that is exactly the potential offered by Eyefinity. Although buying that many monitors costs too much for most of us to enjoy, having it as an option to exploit is nice for when you, say, hit a mid-life crisis wall.

Is that all? Nope, there is a newcomer to AMD's list of software that they added to the 6000 series cards, and you can probably guess what it is for. If you guessed 3D, you win! It seems that everything is going 3D, and it was inevitable that AMD would design something to counter Nvidia's 3D technology. It is simply called HD3D, and it comes standard on the AMD Radeon HD 6990 with the intention of meeting all your 3D needs. We say that it is only an intention because it does not work for all 3D content. The market is split between HD3D and Nvidia's own 3D technology. Few have managed to get their applications to work perfectly for both so far, which means you may or may not always have 3D as an option.

Rendering Technologies

There are three major APIs (application programming interfaces) that are used in graphics and animation, all of which are supported by the AMD Radeon HD 6990. The first and foremost is DirectX. DirectX 11, the latest version, took a few major steps with tessellation and GPU processing. This AMD graphics card embraced these steps and has managed to rival Nvidia's abilities with processing high levels of tessellation. The other two major APIs are OpenGL and OpenCL, both of which are also used for enhancing programming flexibility, performance and functionality. The latest versions of both are supported on the AMD Radeon HD 6990.


The AMD Radeon HD 6990 has a lot of power when it comes to raw graphics processing. However, this graphics card is by no means the perfect, ultimate solution for every situation. It will do everything you want quickly and efficiently, but you have to have the right system and setup for it. Having a jet engine does you no good if you do not have the rest of the plane and the know-how to fly it.

AMD Radeon HD 6990