DxO Optics Pro shows outstanding scalability across CPU cores.
This graph will have the 2013 12 core Mac Pro added soon. It is a fascinating study in both CPU core usage and efficiency of the 2010 generation of Mac Pros vs the 2013 generation.
DxO Optics Pro deserves kudos for utilizing CPU cores in near-perfect scalability. Best of breed in a technical sense; no more efficient raw conversion out there in terms of CPU utilization. Now if only it could use the dual GPUs and cut that clock time down from ~5 seconds per file to ~1 second per file.