GTX460 SLi overclocked, mated and put in context

First up, does anyone use SLi ?

Globally, a tiny fraction of a percentage of PC users have more than one graphics card.

The last time Steam’s all-seeing survey tracked SLi/CrossFire usage, it was around 3%.

Given that the Steam Survey only goes to hardcore gamers, you can see just how pitiful that figure is.

These days, it seems that Steam has now stopped bothering to track multi-GPU usage at all because it is so consistently low (while the weaker, but far more popular, Apple now takes up a sizeable chunk of Steam's analysis).

The continued level of global investment is staggering, so what's behind it?