Let's begin on a positive note. When you don't care about spending a grand more or less, Tones uses their TIZAir system to prove that you can construct a very special high-end system with a basis of two Titan-Z cards. More importantly, the system once again affirms the excellent assembly skills of the Belgian team, which can also be of use to you when you're purchasing a system that isn't quite as pricey. We would recommend choosing different video cards than the Titan-Z ...
As we already mentioned in the introduction of this review, the price / performance ratio of the Titan-Z simply isn't reasonable. Two Titan Blacks are faster, and will save you well over 1000 euros. The main advantage of the Titan-Z lies in that you get comparable performance on a single card. Since it's a three slot card, you can't place one in a Mini-ITX system, which eliminates the possibility of creating a super fast mini system.
Worse yet, the performance of the Titan-Z is simply disappointing in many tests. In the best case scenarios, this correlates with the slightly lower clock speeds of GPU and memory, but we also see many examples of games simply being unable to handle the card. While this can probably be addressed through driver optimizations, that's not something you should be dependent on after spending some 2800 euros. We couldn't help but notice that performance is comparatively better for the UHD resolution than it is for the Full HD resolution; we get the impression that this was the focus during the development of the driver - and that's obviously not a strange choice.
That said, we wouldn't recommend this product to gamers anyway: two Nvidia GeForce GTX 780 Ti or AMD Radeon R9 290X cards often times offer roughly similar performance for only a fraction of the money. Only two Titan-Zs in SLI offer significantly higher performance, but the required investment is incredibly high, to the point where we wouldn't even consider these cards for our Ultimate PC Advice.
As a result, Nvidia stresses that these cards are primarily intended for GPGPU applications in workstations. However, when looking at these benchmarks, we again fail to see a convincing image that justifies the price of these cards. While the green team admittedly takes the lead in various benchmarks, performance is only truly convincing in the double precision benchmarks, where you once again need two of these cards to truly get the best performance by a large margin. We're sure that some applications exist where the expenditure can be justified, where time is money and the extra cost will be paid for - but for the majority of users, we can only conclude that Nvidia's dual-GPU flagship simply isn't the best choice.