HDD or SSD- Which is better A Complete Study

Which is better HDD OR SSD
Which is better HDD or SSD

Which hard disk is good as per our requirement HDD or SSD. 

Hard disks are very important in todays life style. Everything we want to store in large capacity is possible because of these two types disks. So we will know through this article Which is better HDD or SSD.   


Both these drives HDD or SSD are available in market as external storage drives and internal storage drives. 

For internal storage of computers and laptops internal drives are used and for storing data outside computer we are using external storage drives HDD or SSD type.

Internal drives are fitted in computer mother board or circuit board. But external drives are created with casing over the drive and USB interface for connecting to computer and laptop.

Let me explain the features of HDD from HDD or SSD. HDD is a type of storage device. HDD first invented by IBM in the year 1953. Its first commercial use is started in the year 1957. 

It created a new level in the computer data hierarchy. Basically HDD divided into two categories. One is external storage device and another one is internal. 

In laptops or desktops internal HDD or SSD are used. These are open and not in their casing.

But for other storage purposes we can use external storage devices if our system data capacity is low or about to fill.  

You can get HDD external storage devices of various ranges starting from 256 GB, 500GB, 1TB , 2TB and upto 12TB in market.

But in today’s technology all requirements are based on fastness and durability.

Now question will come which is more durable and faster than HDD?

The answer to this question is SSD. SSD stands for Solid state drives. In future HDD will be replaced by SSDs. Because SSDs are faster and durable.

So today we are going to compare the two types of storage drives which are commonly used to store the data permanently in desktop and the laptops.

 Now, conventionally these hard disk drives are used as a storage solution in desktop and the laptop. 

And these hard disk drives are in use for more than two decades. But in recent years, the SSDs or solid state drives are gaining the popularity because of its speed and the performance.

Let’s compare these two drives in aspects like speed and performance, working principle, cost and the storage capacity and many other aspects.

Now we will compare some of its overall aspects of HDD or SSD:

Aspect HDD SSD
Access time(in ms) 100 0.1
Speed of reading (in MB/Sec)  50- 100 200-500
Weight (in gm) 500 50
Power consumption (Watt) 65 3
Price of unit (500 gb) (in Rs.) 1250 7250

Now we will compare the aspects thoroughly to have a better picture of HDD or SSD.



So, first of all, let’s compare these two drives in terms of their speed and the performance.

 Now, the technology of hard disk drive has improved significantly over the past two decades.

And the data density of this drive has increased tremendously. But the speed of hard disk drive hasn’t increased at the same pace. 

Typically, the access time of today’s hard drive is in the range of few ms. And the sequential read or write speed is typically around 100 MBPS.

If you are thinking the speed of the hard drive is not bad then let me tell you that the access time of RAM and the cache memory which is used in the computer is in the range of nanoseconds. 

Which is significantly less than the access time of these hard drives.

So, even if you have very high-end CPU, coupled with graphics card and RAM, still you will not be able to extract the best performance out of that system if you are stuck with the slow hard disk drives.

Now, here don’t get me wrong, with the use of top CPU and GPUs, the performance of the system will definitely increase. 

But because of the limitation of the hard drive, the system boot time and the opening of the applications will not be that fast.

While on the other end, if we talk about the SSDs, they are much faster and have access time typically in the range of microseconds. And typical sequential read and write speed is in the range of 400 to 500 MBPS.

 In fact, even it is possible to achieve the sequential read and write speed in the range of Giga Bytes per second using this SSDs.




So, now let’s look into the internal structure of these drives and let’s find out why SSDs are so fast and hard disk drives are relatively slow in comparison to these SSDs. 

So, if you look inside the hard disk drive, it consists of rotating disk, which is commonly known as the platters.

So, these platters rotate at the typical speed of 5400 or 7200 RPM in laptops. 

And it can go up to 10000 RPM in desktop computers. And in some enterprise hard disk, the speed can go up to 15000 RPM.

So, in these hard disk drive, the data is stored magnetically on these platters using the head. Typically the data is stored in this hard disk drive in form of tracks and the sectors. 

Now, as it involves the mechanically moving parts, there is a limitation on the speed at which the data can be accessed or written on these hard disk drives.

On the other end, the SSDs are designed using the flash memory. And to be precise if I say, they are designed using the NAND flash memory. 

So, as these SSDs are designed using the NAND flash memory, and does not have any moving part, they have very fast access time and very low latencies.

 So, apart from the flash memory, the SSD also contains the micro controller and the small cache memory. So, using the micro controller, the flash memory cells can be accessed or programmed. 

And using the cache memory it is possible to store the incoming and the outgoing data temporarily.


Ok, so now let’s compare the two drives in terms of the form factor. Today’s hard disk drives are typically available in two form factors. 

For desktop, it is available in 3.5-inch form factor, while for a laptop it is available in 2.5-inch formfactor.

On the other end, the SSDs are available in many form factors. The most common is the 2.5-inch form factor, where these drives can be used or replaced in place of hard disk drives.

 Apart from these, the mSATA and the M.2 SSDs are available in very small form factors. And they are used in ultra books and tablets.


 Alright, so now let’s compare these two drives in terms of the system interface. The system interface defines how these drives are connected or interfaced with the system.

So, the earlier hard drives were connected to the system using the PATA interface. Which is known as the parallel ATA.

But today’s hard drives are connected to the system using the SATA interface. While enterprise hard drives are connected to the system using the SAS protocol.

On the other end, if we talk about the Solid  State Drives, mSATA and SATA hard drives are connected to the system using SATA interface. 

While M.2 SSD can communicate with the system using either SATA or PCI express bus.


So, now if we compare these drives in terms of the storage capacity then for the hard disk drive, 1TB capacity is most common in desktops and laptops. 

But for desktops, even 10 Tera Bytes of hard drives are commonly available in markets.

If we talk about the SSDs, then as of now the SSDs are available from 120GB up to 4TB. 

For laptops typically, it is available from120 GB up to 1TB. While for the desktop it is available up to 4TB.


But if we talk about the cost, then these SSDs are much costlier than the hard disk drives.

As of now the cost per Giga Bytes for SSD is almost 3 to 4 times the hard disk drive cost.

But as the demand of SSD is growing, the cost is also reducing. And perhaps one day, it will become as cheap as the today’s hard disk drives.


So, now let’s compare these drives in terms of the power consumption and the reliability. 

These hard disk drives involves the mechanical moving part the power consumption of this drive is more than the SSDs.  

Because of this reason laptops with HDD configuration make sounds and uses more power than the SSD fitted laptops. 

SSD fitted laptops are consuming less power than the HDD configured laptops.


As we know that HDD are having a number of moving parts which are prone to damage and unserviceable at the time of accidental fall or rough usage.

But we know that SSD are having no moving parts in its core or structure. 

So SSDs are less prone to damage and unserviceable at the time of accidental fall or during rough usage.


So, in terms of the data durability, hard drives are more durable and data can be stored for longer times without being powered up.

 Apart from that as we have seen, these SSDs are designed using the flash memory. And because of that the number of programs or erase cycles that can be performed on these SSDs are limited.

Typically, it used to be in the range of 10000 to 100000. And depends upon the quality of the controller as well as the internal structure of the flash memory.

Now, some manufacturers also provide the endurance rating for these SSDs. Typically it is defined by the term drive writes per day. 

It means that the number of times the user capacity of the drive can be written per day over the warranty period. 

For example, if you have 100GB of a drive, which has DWPD rating of 10, it means that 1000GB or 1TB of data can be written in to this drive every day over the warranty period. So, basically, this term defines the endurance rating for the SSDs.

But for most of the users, this rating is quite significant. And even if someone uses this SSD quite extensively then also it will work reliably over more than 5 years.

To know about internal structure of HDD and SSD visit my previous blog “05 LATEST COMPUTER STORAGE DEVICES IN 2020”.


So, overall SSDs have many advantages over the hard disk drives. But as of now, these SSDs are quite costlier than the hard disk drives.

 So, if someone is looking for big storage pull, with the reasonable cost then he can go for the hard disk drive. 

While on the other end, if someone wants very fast performance and willing to pay extra money for that performance then one can go for the SSDs.

I hope you understood the basic differences between the SSD and hard disk drive in this article Which is better HDD or SSD. 

So, if you have any question or suggestions do let me know in the comment section or mail to me.

For more knowledge on different storage devices read my previous blog on “05 LATEST COMPUTER STORAGE DEVICES IN 2020”.

Now you have indepth knowledge of HDD or SSD. So now you know How to have a Fantastic HDD OR SSD With Minimal Spending.

Have a great day!




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