In Depth: Hard Drives

Hard drives are the single component that has most visibly changed. While advances have occurred in memory, processors, or graphics cards, they look the same as they always have, albeit more compact.

Hard drives have changed shape quite a few different times. Sometimes smaller, sometimes larger. A hard drive can be seen as the same concept as a CD, laser disk, VHS, or thumb drive. These are all storage mediums that hold data. If you wanted to, you could manufacture a device that uses VHS tape as a hard drive. However, that may be too costly and archaic for today's standards. I will not be going much into tape-style hard drives, as they are, at this point, used solely for historical backups rather than active storage.

There are three main styles of hard drives: optical, magnetic, and semiconductor. These hard drives are all digital. This means data is stored in ones and zeros. Pit or no pit. High magnetic charge or low magnetic charge. The electrical charge stored or no electrical charge stored.

In the case of optical drives, such as CDs or Laser Disks, they use physical pits in a metallic layer that is read by a laser as the disk spins. These tend to be somewhat fragile, but not really from the CD itself, but the reading head of the drive reading the CD. Shocks, drops, and bumps may cause the head itself to bury into the disk. Even though a plastic coating protects it, damaging the plastic layer can cause read errors on the internal layer. They're also not in favor anymore as their cost per data is relatively high.

The second type of hard drive is magnetic. They are similar to CDs or Laser Disks, but data is stored magnetically instead of a metallic layer being pitted to store data. A magnetic head reads low and high charges instead of a laser head. These drives are much more susceptible to damage as they tend to have no protective layer for a more accurate reading. This type of drive can typically handle much more data in the same space than an optical drive, and the costs of these drives were historically the cheapest. However, prices will likely increase as drives move away from magnetic drives.

The last type of hard drive is a semiconductor. These are your SSDs, NVMe, M.2, or Thumb Drives. Technically, M.2 is an NVMe drive, but I list them separately because the former tends to look much different than their predecessors. An electrical charge is stored in a semiconductor cell instead of storing data on a metallic disc, then spinning and reading them. This technology allows a massive amount of storage in minimal space. As their popularity has been rising, the cost has dropped dramatically. You can store approximately 2,800 CDs in an SSD in a much smaller area than a CD. The downside to SSDs is that they are unforgiving if data is overwritten or in their lifespan. While optical or magnetic hard drives could, in theory, last forever, SSDs will die after a certain number of reads and writes. They will operate nearly normally until they abruptly die. And in the case of manufacturing, they can have defects that affect their life span (could be months, could be a decade).

A fun part of hard drives is how they connect to a computing device. Optical media will typically be inserted into an optical drive connected with an ATA-type connection. External optical drives will use a USB-type connection. Magnetic hard drives are likelier to use SAS or SATA connections, while their external counterparts will also use USB connections. SSDs can use SAS, SATA, or PCIe. The standard, more large form-factor SSDs will commonly use SATA. In contrast, the NVMe or M.2 SSDs will use PCIe connectors.

Having the correct cabling for the type of storage medium is essential. However, this may seem obvious, but SAS and SATA look similar, and the USB connection has probably a dozen or so different shapes. The current standard is USB 3.1, and the Thunderbolt or Type-C connector is becoming the most ubiquitous.

As mentioned earlier, the main thing that hard drives are susceptible to is damage from drops. Additionally, they can also be vulnerable to damage from electricity and water. Ensuring you protect the hard drive is more important than the other components. Albeit the other components will probably be more expensive, you do not lose data if they die. You will lose data if your hard drive fails.

As hard drives have shrunk or changed styles, many older types have faded out of usage or been removed entirely. In the case of laptops today, you will not find a magnetic or optical drive. You will only find SSD-style drives (and most likely an M.2). At this point, you will most likely have an M.2 hard drive connecting with a PCIe slot on a motherboard or an external hard drive that connects with a USB cable.

It would be best if you always had backups of your data. If you have a hard drive, you should have a second with a copy of the data. Additionally, you should have an offsite backup or online backup. The last thing you want to do is lose everything you stored over the years.