The difference between HDD and SSD | HDD vs SSD.

In computing, static storage or secondary memory refers to the medium on which persistent data is stored. The computer writes information on a hard drive to ensure that information is not lost when the computer is turned off or rebooted.

Hard disks are available in a variety of storage capacities and types. Hard disk drives (HDDs) and solid state drives (SSDs) are the two main types of persistent storage.

Each type has its own cost and performance metrics. Which option is suitable for a user depends on the budget and performance requirements.

In this tutorial, we will describe each type and make a detailed comparison between the two.

What is HDD?

An HDD type of storage can be internal or external to a computer. When internal, it connects to the motherboard using data buses. For external, it uses USB connectivity or C-Type. Data is stored magnetically on a spinning disk, which is read and written with the help of a moving head.

There are magnetic circles, each circle divided into basic units called sectors. When a program needs to access the data, heads move to that block or sector and perform read or write operations.

The HDD is the legacy storage technology. The existence of Hard Disk Drives was before the invention of SSD. They are cost-effective for storing any number of files, and inside the computer, they come in two sizes, 3.5 inches for desktops and 2.5 inches for laptops.

What is SSD?

If you are a student of electronics, you might hear about solid-state devices. In this, a device is in the form of an electronic chip. In contrast to the HDD, it does not have any moving parts. That increases speed by eliminating the time needed to spin the disk and head moment.

Till now, per GB storage in SSD is costing higher than HDD. But with the advancement in technology, SSDs are getting cheaper day by day. A laptop with SSD will cost more but will be faster and thin in size.

What are the differences between the two (HDD Vs. SSD)?

Variable Access Time –  With the traditional HDD, the data access time depends on the location of data over the disk. If it’s close to the head, reading will be faster. For example, the disk and head will move multiple times if a file is not stored at a contiguous location.   While with SSD, this is not the case.

Hardware failure –  The HDD has mechanical parts if there is a slight alignment problem or if a disk falls from a height. There are high chances of damage as compared to the other.

How SSD is advantageous-

  • Data Access speed in SSD – Unlike the HDD,  the access time for data is the same whether the data is contiguous or not. This results in no need for defragmentation while storing data.
  • Easy to Carry – You can carry an SSD easily without worrying about damage while moving.   Do not have movable parts, so lesser are the chances of damage by the vibrations on the move.
  • Power Consumption– SSDs do not have mechanical parts that enable them to consume less power than HDDs.  Suits well in computing equipment for longer battery life.
  • Lesser Noise – You might hear a noise inside the computer while accessing a file. It’s because the mechanical components create friction in HDD. SSD does not have such a thing, so there is no noise.

Are there any disadvantages to using SSDs?

Till now, we have seen that SSDs are better in all aspects of data storage. Both can store a large amount of data, but SSD performs better. But is there any disadvantage? Yes, nothing comes for free, so a better experience is more costly. SSDs are pricier than HDDs. It can even be four times or more expensive. A beginner with a lesser budget opts for HDDs.

Another thing is that SSD is based on NAND technology. It uses integrated circuits that use NAND gates for storage. When a block of data needs to write, all data is rewritten to the memory, unlike the HDD, where only a block or multiple blocks of data is written.