The recently acquired HP Z4 G5 Xeon workstation CPU just don’t get past 4Ghz threshold?

According to Intel turbo boost Max spec, W3-2435 Xeon theoretically can go 4.5Ghz single core without thermal throttling. My CPU idles at 43 deg C, and max well below 65 deg Celcius. The process never pass 4 Ghz.

Single core speed is important to me since I use Solidworks which is a single-cored application for modeling unless I run simulation for CFD which will utilizes all 8 cores.

Is there something I need to tweak in BIOS?

https://preview.redd.it/shf8xfgyoq0c1.png?width=350&format=png&auto=webp&s=ca6a2af7135e8dd1a45b4dd78f9813183be4ce9d