How does the computer store the files?

The computer stores the files, currently with a hard disk but sometimes also with solid state disks, the first has a disk and a very sensitive mechanical arm, and the other has only electronic chips.

The hard disk consists of a controller that does the entire process of connecting to the computer's data bus and thus converting its signals and pulses to a controller chip that in turn will demand other mechanical tasks for the disk to rotate, for the arm to walk to a certain position, and thus read the disc's track and retrieve the information or record whatever is necessary.

But the hard disk has its days numbered, as there are many new features ahead, which will replace these hard disks, which, compared to new technologies, are not so hard anymore.

Before the "Hard Drive" era

When computers started to appear, there were no hard drives, all data was saved in RAM as well as a calculator today, and if the computer was turned off, it would have to reprogram it and enter all the information again to continue.

As it started to get too complex to return the information and continue where it left off, they made several ways to speed up the process, such as punched cards, where they already had the essential programming to upload the system, and thus start working again.

Image showing a punched card and a pen-drive of the present day.

Right after the punched cards, they developed magnetic tapes to store more content, as well as music tapes or videocassette tapes that stored videos in an analog way.

Magnetic tape for storage

K7 tape, using magnetic tape for use in audio recordings.

As it was very difficult to have to rotate the tape back and forth whenever it was necessary to open a file (it could take a few minutes for the tape to rotate the position needed to read the data), it was necessary a more flexible media, wherever it was It is possible to read this information without having to rotate the tape from side to side, avoiding the constant problems of breaking the tape.

Soon pizza-shaped media emerged, both on hard disk media enclosed in secure chambers and floppy disks. The current generation may have never seen a floppy disk in their lives.

8 'inch, 5' 1/4 and 3 '1/2 floppy disk.

Floppy disks were more popular due to their reduced cost, but as soon as hard drives became "smaller", and with more storage capacity (somewhere around 2 MB of data), people were able to automatically load the computer without need to keep changing floppy disks.

Windows itself, in its older versions, such as Windows 1.0 and Windows 2.0, operated only with floppy disks, and hard drives with some compatible controllers, but it was only on Windows 3.11 that it was officially installed on the machine's local hard drive, and no more on floppy disks.

In 30 years, hard drives have gone from $ 100,000 per Gigabyte to cents (currently).

After the "hard drive" era

A lot of time has passed with computers using elementary hard drives inside, with no alternative for almost 15 years.

We currently have several other alternatives, and many others are being researched, but the most common, currently financially even affordable and much faster are solid state drives, SSD drives.

A hard drive delivers 70 MB / s against 550 MB / s for an SSD.

Many older computers also support SSD, as many of these new drives are designed to use the same communication interface as hard drives.

However, solid state disks, as they have no mechanical part, and have a much shorter access time, and with their constant evolution, can no longer be limited to the current hard disk interface, which has a maximum theoretical limit of 600 MB /s.

That is why innumerable cards and proprietary controllers have appeared, and these cards with storage chips soldered on the cards, delivering from 800MB / s to 1000 MB / s.

OCZ RevoDrive connected to a PCI-e bus, even if it connects video cards.

Other manufacturers also started making their versions, until then a group of companies realized the real need to standardize or there could be huge compatibility problems between these devices, and then a new standard was created for specific use for solid state drives, which enjoy all its advantages.

Until then, the interface, the bus, was made for low latency, since a hard disk takes in milliseconds, thousands of them to access compared to a solid state disk.
Solid state drives, on the left, using the same size of hard drive and the same interface, the other side, cards that are connected on the PCI-e bus.

PCI-e over the NVMe standard, using the PCI-e port.

In view of so many proprietary forms, two new communication standards have emerged, SATAe and NVMe, both connected to the PCI-e bus today.

The idea of standardizing is more than necessary to prevent each manufacturer from spending time and engineering developing new exclusive designs, increasing the final price, and preventing standardization, interoperability, and compatibility between operating systems, while also avoiding the development of multiple drivers for several systems.

Diferença no método NVMe vs AHCI.

The difference from the AHCI standard to the new NVMe method, as shown in the graph above, consumes less computational resources than the previous standard.

SSD disk using NVMe, over the PCI-e bus.

Card that connects NVMe-based SSD to DELL PCI-e 16x bus for desktop computer.

With this, the new BIOS of computers, may have programs such as allowing to boot an operating system natively.

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