Question: what are the needed requirements when doing manual overclocking?
Answer: The CPU.
So far, Intel manufactures the CPUs with the highest quality, hence the probability of a successful overclocking is highest with Intel CPUs.In case you want to overclock a Pentium 133, try to avoid the 'SY022'. ... 
The Motherboard.
The quality of the motherboard is crucial for successful overclocking! ... 
The RAM.