n=6?

Amdahl's law has been telling us for over 4 decades that throwing more cores at a problem quickly reaches the point of diminishing returns. For the last decade or so the workloads and CPUs dictate that more than about 6 cores doesn't buy much if anything in extra performance. For the average PC, most users won't ever see any improvement with more than 6 cores so I expect that to remain the high performance sweet spot for years to come.