Okay, but none of the individual cores are reaching 100%. Ergo, no CPU throttling. I specifically said core in my original post. Am I still missing something?
He's right. That's not the way that Multi core CPUs work. A single thread will not run on just one core - it will jump across different cores, one at a time. On an 8 core system, one thread running at 100% can and probably will) look like 12.5% of your entire system. One individual core will not run flat out while the others are idling.