Manual overclockers are welcome to try their hand at squeezing extra performance out of AMD’s Ryzen 9 3900X, which has a base clock of 3.8 GHz, but they shouldn’t expect to hit frequencies beyond 4 to 4.1 GHz at safer voltages. Binned-CPU retailer Silicon Lottery found that only 35% of their chips managed to hit 4.15 GHz (1.237 V), while a paltry 6% reached 4.2 GHz (1.250 V).
4 GHz seems to be guaranteed, however, as Silicon Lottery saw a 100% pass rate for that frequency at 1.2 V. 4.05 GHz is also doable (87% @ 1.212 V), but the odds begin turning poor at 4.10 GHz (4.10 GHz @ 1.225 V) and upward.
All Ryzen 9 3900X CPUs tested by Silicon Lottery were able to hit 4GHz across all-cores (via Techquila). 87% could hit 4.05GHz, which is a sharp drop-off for a marginal clock speed increase. However, the most drastic pass rate decline is between 4.10GHz and 4.15GHz.