Question - i5-9400F refuses to boost to 4.1GHz on a single core. | Tom's Hardware Forum
Intel Core i5-9400F 2.9GHz CPU Grey | Techinn
CPUs - Intel Core i5-9400 2.90GHz (Turbo Boost up to 4.10GHz) 9MB SmartCache, 6x Threads LGA 1151!! was listed for R2,199.00 on 8 Feb at 03:16 by Gee Traderz in Cape Town (ID:577372522)
Core i5-9400F - Intel - WikiChip
Simple Ways to Enable Turbo Boost on I5: 6 Steps (with Pictures)