Conclusion

Alas, the quad-processor platform made out of two GeForce GTX 295 cards is a complete disappointment. And this is not the first time that Nvidia’s Quad SLI solution is such a failure. The two earlier generations of this technology, based on GeForce 7900/7950 GX2 and GeForce 9800 GX2 cards respectively, were not quite successful, either. Notwithstanding the fourth GPU, the Quad SLI platform was inferior to its triple-GPU counterpart based on GeForce GTX 285 in quite a lot of games.

Let’s view the results in more detail.

The average performance growth of the Quad SLI platform relative to the single GeForce GTX 295 is a mere 18.5%. It is only in three tests (S.T.A.L.K.E.R.: Clear Sky, Devil May Cry 4 and Prince of Persia) that the performance boost was higher than 60%. The Quad SLI tandem could only outperform the GeForce GTX 285 3-way SLI in five tests, its advantage being less than 15% in two of them. Nvidia’s solution is overall better than the Radeon HD 4870 4-way CrossFireX, but the latter enjoys a considerable advantage in three tests.

The resolution of 1680x1050 can hardly be interesting for top-end multi-GPU products but we can note that the GeForce GTX 285 3-way SLI looks better here than the GeForce GTX 295 SLI. The latter only has a large advantage in S.T.A.L.K.E.R.: Clear Sky. Otherwise, its advantage, if any, has no practical worth.

The resolution of 1920x1200 is quite popular among users of top-end gaming systems, but it is the GeForce GTX 285 3-way SLI that turns in the best results here. Assembling a graphics subsystem out of two GeForce GTX 295 makes no sense. You can even have a performance hit in some newer games, e.g. Call of Juarez: Bound in Blood, for which there are no driver optimizations as yet.

Well, it is the resolution of 2560x1600 that 3- and 4-way multi-GPU systems are meant for. Besides GPU performance, the amount of onboard graphics memory can be a factor here, and the GeForce GTX 295 SLI is inferior to the GeForce GTX 285 3-way SLI in terms of memory. The former subsystem is ahead by an average 2%, but is still worse in Call of Juarez: Bound in Blood. The difference between the two solutions cannot be felt in practice in S.T.A.L.K.E.R.: Clear Sky and Devil May Cry 4.

The GeForce GTX 295 SLI platform is good in terms of scalability. The doubling of GPUs leads to an average 47% performance growth, the peak performance boost being as high as 60% or even 90%. Building a Quad SLI system to play Crysis Warhead still has no point because no graphics solution available today can deliver a playable speed in this game at high resolutions. The level of comfort grows up, however, in such games as S.T.A.L.K.E.R.: Clear Sky and Prince of Persia, especially in action-heavy scenes.

Thus, the Quad SLI platform is formally the most advanced multi-GPU solution Nvidia offers today, but it is often inferior to the 3-way GeForce GTX 285 platform in practice. The latter is overall preferable, except when it is impossible to build (e.g. your mainboard has only two PCI Express x16 slots or the slots are located in such a way that you cannot install a third card into your system case).

Generally speaking, we consider Nvidia’s Quad SLI and 3-way SLI as well as similar solutions from AMD/ATI a compromise. They have a number of inherent drawbacks that can be hardly eliminated even theoretically. They are bulky, noisy, power-hungry and must be supported on the side of the driver and game. Buying a $1000 graphics subsystem, you want to have maximum performance out of the box, but today’s multi-GPU solutions can’t offer it. On the other hand, for some enthusiasts the very process of building, setting up and benchmarking a multi-GPU subsystem to set new 3DMark records is a pleasure, but that’s far from what gamers want.