I saw a reddit post on how to achieve advertised boost for the 3900X. Have it on a BIOS with AGESA 126.96.36.199 that delivers 1.53-1.55V on boost and they deliver their advertised boost frequency.
All new BIOS limit VCORE @ 1.500V tops and that's why I presume we aren't hitting the BOX /advertisement speeds.
They where binned for 1.550V to hit their max frequency but new BIOS deliver only 1.500V.
I remember some dead cpu's @ launch for some people when they played around with them with too high LLC I recall mentioned.
1.550V + high LLC? how much voltage would be delivered? It was too much. I think we aren't meant to use LLC unless doing MANUAL OC. (LLC with PB & PBO behaves weirdly)
I tested and put a slight +0.0250V offset with PBO and my cpu started to increase it's max boost slightly getting closer and closer with more voltage to the real frequency it should run at.
Though I don't know if 1.550V is really what they should of ran at launch for single core boost. Pure speculation. But the increased voltage helps the CPU to boost higher.
Take this as you wish as a thought I had when I saw that reddit post and all the talk about this stuff on the net.
Gigabyte X570 AORUS XTREME, Ryzen 7 3800X 4.45Ghz, 4266/1900 MEM/FCLK, 188.8.131.52.76.tRFC 650 1T 1.58V
4x8Gb Kingston HX434C19FB2K2/16 3466C19 1.2V (Micron E-die 16nm)
OLD: Biostar x470GT8 Ryzen 7 1700 @ ~4.0Ghz CPU, 3200Mhz RAM ...