Thank you for the reply. No, the 3900X does not run 100% cpu utilization since I proved that when I asked that owner to build the exact same scene as the one I was testing. However, his processor built that lighting 2 seconds faster than mine.
Your comment that the 3900x is a better processor seems to be countered on quite a few benchmark tests. However, benchmarks are what they are but what concerns me is some of the real world testing that was apparently done here.
https://www.pugetsystems.com/labs/articles/Unreal-Engine-AMD-Ryzen-5000-Series-CPU-Performance-1967/
If you look at the Unreal Light builds, the 3950x appears to be quite faster than many processors. However, as I mentioned in that post, our group was getting 100% cpu utilization the whole way through the light build in an older Intel I7 cpu where the 3900x and 3950x were not. The build times between the two were substantial. I wanted to believe in my Ryzen 3950x but how do I argue what I am seeing in a real world application?! I will say it does really well in my offline renderers like Vray.
This experience stinks for me because I had ventured to AMD some time ago once before with a CPU and a graphics card. That experience was less than satisfactory and now this one is beginning to look that way as well. It is not helping that some people are telling me that Intel has their cpus optimized for some of these Unreal tasks and AMD has none.
I would say updating my chipset drivers and/ or bios may help but we have the same results on two completely different machines. One is literally brand new (3 weeks old). I do not know what the answer is.