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I have 4 HDDs here with me, from 3 different manufacturers, and all of them have the following 4-pin extra interface beside the SATA connector:

HDD with 4-pin interface

HDD with 4-pin interface

Looking on the internet, I can see that it exists on all HDD devices, but not on SSDs:

SSD without 4-pin interface

SSD without 4-pin interface

On old IDE devices, there was a similar interface used to select operational mode (master/slave), but on SATA it doesn't make sense anymore.

Could someone tell me what this interface is intended to do and why it doesn't exist on SSDs? It is used in any practical situations?

Rohit Gupta
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Diogo
  • 30,792

3 Answers3

84

Those are jumper settings, similar to the IDE drives you mention, but for SATA specific options depending on the drive maker. For example, on this Western Digital support page for mobile drives, it shows two options:

enter image description here

Also, it doesn't exists on SSDs because there is no spinup or spread spectrum related to solid-state devices.

@Adrian Cox mentions in the comments below, a different pin function for Seagate drives.

jdh
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5

According to what i can find its a Manufacture specific firmware terminal that aids in HDD recovery. PC USB Terminal adapter There's a few images on this particular page that shows how to connect a USB cable to those ports using Manufacture specific adapters.

Drew Malone
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-1

That's a temperature port compatible for imac

Suparno
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