USCIS.gov is the best source of info on petition processing times. I-129F is the petition, not the visa. The petition is adjudicated at the California Service Center, and approved petitions are sent to NVC, where it is eventually dispatched to the appropriate consulate. There is much more variation in this second part, driven by consular workloads. Some consulates are so backlogged that that phase of the process (NVC to interview date) can take up to a year, some are much faster. Best source of consulate-specific processing times is probably the VJ portal for your country.
Current petition processing time according to USCIS is 16 months.