The possibility of pairing up graphics cards in order to increase the overall graphics subsystem strength is nothing new. Ever since the golden days of 3dfx and the first SLI mode (which was not the same as today’s Nvidia SLI) have two graphics cards in a single PC been an option. To be honest, only the last few generations have made this concept practically usable, meaning that the gain from using two cards instead of one has a significant performance impact compared to the doubled price required to be paid. Actually, most users still think that two graphics cards equals double the performance, but that’s not exactly the case. Still, that isn’t to say that a long period of time hasn’t passed since gains of 30-50% were considered good, and on the other hand, ATI and Nvidia have kept on increasing the number of Radeons/GeForces one can place inside a single PC.
This is how technologies such as 3-way SLI and CrossFireX were born, and for the time being, having more than four graphics cards working in parallel in a single PC is not on anyone’s roadmap. A few years ago, the situation was very clear: SLI and CrossFire were capabilities that meant something only in the marketing and PR segments, with low practical usability. The situation is much better today, even compared to the last generation (the Radeon HD 4000 series, for example).
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