Here is CPU frequency world records - https://valid.x86.fr/records.html
Anyone from forum can also share his/her results.
This site has also other interesting topics - CPU Cores Distribution, GPU Manufacturers, RAM memory capacity - https://valid.x86.fr/statistics.html
And there is also CPU- Z, free system information software for 32bit and 64bit OS - https://www.cpuid.com/softwares/cpu-z.html
Tip: CPU overclocking can lead to new PC/laptop buying from CPU damage.