I have Intel Core i5 9400F installed on my system. I found that it never works on the maximum x41 multiplier. IIsee the following when CPU-Z benchmark is running:
Can I force it to work on the maximum speed, does it depend on the system / BIOS configuration?
The clock multipliers that the individual cores can reach is based upon a whole slew of factors, primarily including the number of cores active and the overall thermal headroom available. The BIOS defines the maximum clock multiplier that will be used by the active cores based upon the number of cores that are actually active. Some BIOS make this table available for modification and some don't. If you cannot find these configuration parameters within your system's BIOS, you will need to discuss this with your motherboard/system manufacturer.
For more information on the Turbo Boost feature, you can consult these sources (amongst others):
Hope this helps,