Thanks for the pointer to the Intel utility; I had not heard of it.
My system is running an Alienware BIOS which has fairly limited controls. There's also an Alienware OC Utility which has slightly better controls but nowhere near the Intel ones.
The image below is what the Intel utility says for my various configs. On the left is "Default" (according to Intel). Next column is what Alienware configures when OC is "off". Column 3 is "OS Stage 1" and Column 4 is "OC Stage 2". Basically the final 3 columns should correspond to my bench numbers.
Some things are definitely confusing, like what is "Max Non Turbo Boost Ratio"? Is that when there are 0 active cores? Also, running MAME and watching the live value of "Active Cores" often showed 0 and no more than 1.
(Sorry for the large size, I run high DPI and I forgot to scale it down.)