Why do some hard drives still have pins on the back?

More than one may have been surprised to see that their hard drive still has a series of exposed pins on the back. However, when we mount these on our PCs, it doesn’t seem like we should connect them to any cables or connectors. So what is the function that they perform in those storage units? And why SSDs neither use nor have they ever used them? These questions are what we will answer in this article.

The hard drives are being used in consumer computing practically since the beginning of it. In fact, the first 10 MB hard drives date back to 1986, although they did not become popular among users until the following decade of the 20th century.

Back then, all hard drives were connected to the PC using the PATA (Parallel AT Attachment) standard. In this standard, the disks were connected to “girdle” type cables, where there used to be two connectors for each cable. This meant that the units had to be manually configured as “Master” or “Slave” depending on how we wanted them to perform one function or another, and in those times this was something that the user had to know how to do.

Precisely for this there are the pins on the back of the hard drive, because there were connected some jumpers that were used to configure it in master or slave mode. For the operating system and the BIOS this was of vital importance, because it was only capable of booting from the master hard disk, never from the slave, even if we had an operating system installed there too.

As you can see in the image, according to the pins that closed the jumpers, the configuration of the unit could be carried out. All this is no longer useful when the first SATA disks appear , since in this standard there are no Master or Slave drives. They are all treated the same, as it is a point-to-point communication, which is why SATA cables only have one connector per end, not like PATA that with a cable we could connect several hard drives.

The rear pins of the hard drive are useless anymore

The first SATA hard drives to hit the market used the SATA 1 or SATA 150 standard. This meant that their maximum data transmission rate could only reach 150 MB / s. The next generation, SATA 2 or SATA 300 doubled this data transmission rate, up to 300 MB / s. But, when used on older motherboards, for the old SATA 150m standard they could have compatibility issues. For this reason, some pins were put on their back.

With them, the performance of the hard disk could be limited to SATA 150. And they were back to being compatible with the old motherboards.

However, in the latest models, and taking into account that there are no longer motherboards so old that they need this limitation, the pins have other functions. But these functions are intended for advanced users. For example, some brands of discs allow you to use jumpers with the pins to activate the Spread-Spectrum Clocking function . While other pins allow to activate the Advanced Format feature, which was present in older versions of Windows.

Therefore, unless you are that type of user, who needs to make use of these very atypical functions within the current consumer computing landscape. Most users do not care if these pins are there. Because most of us are never going to use them.

Why do SSDs lack these pins?

The answer is simple: these pins were developed to work with mechanical hard drives, and indeed with older generation hard drives; the SSD meanwhile have an internal operating mode very different from that of these, which means they do not need this type of pin to access advanced operating functions.

Also, as you know, there are no SSDs that have an IDE / ATA interface and, therefore, at least you will need a SATA interface to use an SSD and this lacks the possibility of connecting several devices on the same cable, so it would be useless incorporating these pins.

 

by Abdullah Sam
I’m a teacher, researcher and writer. I write about study subjects to improve the learning of college and university students. I write top Quality study notes Mostly, Tech, Games, Education, And Solutions/Tips and Tricks. I am a person who helps students to acquire knowledge, competence or virtue.

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