Maybe four has no relevance, but then neither does three, or even possibly two for 90% of 3d applications currently available. But I would imagine anyone bothering to use more than two 480s, would be aimed more or less at number and performance crunching, which would of course include 3dMark, other synthetics/folding etc. Either way, you'd have to over volt the cards to enable overclocking that returns any significant or noticeable performance difference, and then you'd be resorting to better cooling. But how exactly do you fit full face water blocks onto multiple GPUs that are slotted in each adjacent PCI-E lane? That would be a seriously long motherboard.