ConclusionAlthough the Radeon HD 6990 does indeed break new records, this isn’t always a positive thing unfortunately. While obviously part of the line of previous generation bi-GPU Radeons, the high energy and noise issues on previous generation cards are amplified when it comes to the HD 6990. If you want to sufficiently dissipate 375 to 450 watts, how else are you going to do it than by running your fan loud and fast?
If this is going to trouble you, it’s best to admit it right from the start – you’ll be better off with a couple of GeForce GTX 570s in SLI, a high end bi-GPU solution but with more acceptable noise levels, though with similar energy consumption.
With PowerTune, we thought that AMD would be giving us a rather tame Radeon HD 6990, but they had other ideas: they wanted to develop a power hungry monster and take the thermal envelope way over 300 watts to 375 watts and even 450 watts! One of the particularities of this model is that it has two modes, each with different clocks and energy consumption limits.
Using the 450 watt mode, although on the one hand recommended by AMD, should however be considered as killing the guarantee. It has above all been designed with a view to offering a margin for overclocking and limiting the GPU less during very heavy loads. In practice, in games, it only brings a small gain in comparison to the 375 watt mode. We therefore advise you to use this second bios, especially as you ought to be able to keep noise levels down if you take care to cool your casing properly.
On sale at €600, this card is obviously aimed at a limited market, especially as the Radeon HD 6950 and 6970 in CrossFire offer a similar price/performance ratio, a little less noise and a different shape/format which will be easier to adapt to a higher number of boxes. The Radeon HD 6990 will be useful above all for setting up an extreme system without having to monopolise all the slots on your motherboard or requiring an XL-ATX model, by adding a second Radeon HD 6990 or just a Radeon HD 6970. The graphics power you’ll then have at your disposal will allow you to benefit fully from surround gaming.
For AMD, the main thing about this card is that it allows it to hold onto the no.1 spot on the podium in terms of performance. While it seems clear that the forthcoming GeForce GTX 590 would have had no trouble facing down the Radeon HD 5970, the Radeon HD 6990 is another proposition altogether and it looks as if a hotly contested duel is on the way!
To finish up, a word on the drivers. A few small performance issues with the latest drivers remind us that they play a primordial role in the correct functioning of any multi-GPU system. Almost 6 years after the advent of these systems, we would have liked them to feature less prominently in our analysis. AMD has taken a step in the right direction by allowing a simple update of the application profiles and a second step will be the implementation of an automatic update, which shouldn’t be long in coming. All they’ll then have to do is avoid reintroducing a whole lot of bugs where everything was already working correctly!