Adapters that can convert a 4-pin Molex connector to a SATA power connector exist. However, because the 4-pin Molex connectors do not provide 3.3 V power, these adapters provide only 5 V and 12 V power and leave the 3.3 V lines unconnected. This precludes the use of such adapters with drives that require 3.3 V power. Some 4-pin Molex to SATA power connectors have electronics included in the connector to also provide the 3.3 V power. Understanding this, drive manufacturers have largely left the 3.3 V power lines unused.
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