Slimebeast on 31 August 2012
SLI-scaling is mostly determined by drivers tweaked by Nvidia and obviously the specific GPU in question, rather than the game developer's support. Generally speaking SLI-scaling nowadays is of good quality in all modern titles and hovers around 70-90%.
And CPU-scaling beyond 4 cores is simply a non-issue in games that are bottle-necked by the GPU, such as Metro: Last Light. The extra CPU cores will not increase performance, no matter how many they are.
The CPU part is just laughable PR talk.
