SOLID STATE DRIVE OR HARD DISK DRIVE

A hard disk drive (sometimes abbreviated as Hard drive, HD, or HDD) is a device used to permanently store and also retrieve information. There are many variations, but their sizes are generally 3.5" and 2.5" for desktop and laptop computers respectively. A hard drive consists of one or more platters to which data is written using a magnetic head, all inside of an air-sealed casing. Internal hard disks reside in a drive bay, connect to the motherboard using an ATA, SCSI, or SATA cable, and are powered by a connection to the PSU (power supply unit). The hard disk was first introduced on September 13, 1956 by IBM.

A Solid-State Drive or Solid-State Disk, SSD is a drive that uses non-volatile memory (you can turn off the disk and it won’t “forget” what was stored on it) as a means of storing and accessing data, much like computer RAM. Unlike a hard drives, an SSD has no moving parts. An SSD may also be referred to as a flash drive (SSD can be thought of as an oversized and more sophisticated version of the humble USB memory stick), which should not be confused with a USB jump drive or Adobe Flash. The first SSD was implemented in IBM supercomputers in the 1970s and 1980s and became popular during the rise of netbooks in the late 2000s.

 

Solid-state drives actually aren't hard drives in the traditional sense of the term, as there are no moving parts involved. A traditional hard disk drive (HDD) consists of a spinning disk with a read/write head on a mechanical arm. An SSD, on the other hand, has an array of semiconductor memory organized as a disk drive, using integrated circuits (ICs) rather than magnetic or optical storage media.

SDD and HDD Comparisons

Now, let us go to the comparisons between the two drives for a guide to choose what fit most into our personal needs.

Form Factors

HDDs are usually 3.5" and 2.5" in size, for desktop and laptops respectively with no options for anything smaller. 

The Solid State Storage Initiative (SSSI) has identified three major SSD form factors for the enterprise: SSDs that come in traditional HDD form factors and fit into the same slots (It comes in a standard 1.8”, 2.5”, or 3.5” size that can fit into the housing and connectors for the same-sized hard drives.), Solid-state cards that use standard card form factors(It comes in a standard 1.8”, 2.5”, or 3.5” size that can fit into the housing and connectors for the same-sized hard drives), such as Peripheral Component Interconnect Express (PCIe), and reside on a printed circuit board (PCB), and Solid-state modules (SSMs) that reside in a Dual In-line Memory Module (DIMM) or small outline dual in-line memory module (SO-DIMM), and may use a standard HDD interface such as Serial Advanced Technology Attachment (SATA).

Performance

SDD starts almost instantaneous; no mechanical components to prepare and may need a few milliseconds to come out of an automatic power-saving mode. But Disk spin-up in HDD may take several seconds. A system with many drives may need to stagger spin-up to limit peak power drawn, which is briefly high when an HDD is first started.

If data from different areas of the platter of HDD must be accessed, as with fragmented files, response times will be increased by the need to seek each fragment.  Read performance does not change based on where data is stored on an SSD.

SDD is better because of the distinct performance advantages they have over HDD (even the highest performance electromechanical HDD), these include faster access times and lower latency. A typical HDD takes about 5,000 to 10,000 micro-seconds to access data where as a SSD has access speeds of 35 to 100 micro-seconds, which is nearly 100 times faster. This faster access speed means programs can run more quickly, which is very significant, especially for programs that access large amounts of data often like your operating system. Thus, end users typically enjoy much faster boot times in SSD compare to HDD.

Noise and Vibration

In general, SSDs are more durable and much quieter than HDDs, with no moving parts to break or spin up/down (With no moving parts SSD generates no noise). With the spinning platters and moving read/write heads an HDD can sometimes be one of the loudest components in your computer. Even the quietest HDD will emit a bit of noise when it is in use from the drive spinning or the read arm moving back and forth and faster hard drives will make more noise than slower ones. 

No vibration as there are no moving parts in SDD where as the spinning of the platters in HDD can sometimes result in vibration. Though there is a set of features in some Hard disk drives called Sound Barrier Technology that include some user or system controlled noise and vibration reduction capability.

Power consumption

The SSD uses less power than a standard HDD, which means a lower energy bill over time and for laptops an increase of battery life. With all the parts and requirements to spin the platters the HDD uses more power than an SSD. High performance flash-based SSDs generally require half to a third of the power of HDDs. But high-performance DRAM SSDs generally require as much power as HDDs, and must be connected to power even when the rest of the system is shut down.

Lifetime and Reliability

SSDs have no moving parts to fail mechanically. Each block of a flash-based SSD can only be erased (and therefore written) a limited number of times before it fails. The controllers manage this limitation so that drives can last for many years under normal use. HDDs have moving parts, and are subject to potential mechanical failures from the resulting wear and tear. The storage medium itself (magnetic platter) does not essentially degrade from read and write operations.

It is true that SSDs wear out over time (each cell in a flash memory bank has a limited number of times it can be written and erased), thanks to TRIM command technology built into SSDs that dynamically optimizes these read/write cycles, you're more likely to discard the system for obsolescence before you start running into read/write errors.

For both consumer and enterprise-grade HDDs, their average failure rate is 6 years, and life expectancy is 9–11 years. Leading SSDs have overtaken hard disks for reliability; however the risk of a sudden, catastrophic data loss can be lower for mechanical disks.

When stored offline, (unpowered in shelf) in long term, the magnetic medium of HDD retains data significantly longer than flash memory used in SSDs. As of 2011 leading SSDs have lower return rates than mechanical drives. Many SSDs critically fail on power outages; a December 2013 survey of many SSDs found that only some of them are able to survive multiple power outages.

Operating temperature

Comparing their operating temperature, most modern HDDs can operate at 0 °C (32 °F) and SSDs can operate at −55 °C (−67 °F). Thus, SSD can operate at lower temperature. Ambient temperatures above 95 °F (35 °C) can shorten the life of a hard disk, and reliability will be compromised at drive temperatures above 131 °F (55 °C). Fan cooling may be required if temperatures would otherwise exceed these values. In practice, modern HDDs may be used with no special arrangements for cooling.

Susceptibility to environmental factors

HDD heads floating above rapidly rotating platters are susceptible to shock and vibration. SDD do not sensitive to orientation, vibration, or shock and usually no exposed circuitry. HDD circuitry may be exposed, and it must not be short-circuited by conductive materials (such as the metal chassis of a computer) and should be mounted to protect against vibration and shock. Some HDDs should not be installed in a tilted position.

Moving from a cold environment to a warmer environment, SSDs have no issues on this but a certain amount of acclimation time is needed when moving HDDs from a cold environment to a warmer environment prior to operating it; otherwise, internal condensation will occur and operating it immediately will result in damage to its internal components.

SSD is not affected by magnetism but because a hard drive relies off magnetism to write information to the platter, information could be erased from an HDD using strong magnets.

Cost (Price)

SSDs are more expensive and their pricing changes rapidly: US$0.59 per GB in April 2013, US$0.45 per GB in April 2014, and US$0.37 per GB in February 2015. HDDs cost about US$0.05 per GB for 3.5-inch and $0.10 per GB for 2.5-inch drives.

The price of a solid state drive is much more than an HDD, which is why most computers with an SSD only have a few hundred gigabytes of storage. Desktop computers with an SSD may also have one or more HDDs for additional storage. HDD is much cheaper than SSD, especially for drives over 500GB.

Which one best for the needs?

Do these mean the SSD is far better than an HDD? Not at all! As we mentioned earlier, it all depends on individual needs. The comparison here is just to lay out the pros and cons for both options. To aid you even more, here are some rules to follow when you decide which drive is best for you:

An HDD might be the right choice if:

• When you need more storage capacity, up to 6TB (though with SMR technology new drives can have up to 10TB)
• Want to spend money with fewer budgets for your drive.
• When you don’t care too much about how fast a computer boots up or opens programs, then get a hard drive (HDD).
• If there is urgent need of Drive storage, quickly obtain one HDD

An SSD might be the right choice if:

• You are willing to pay for faster performance
• Don’t mind limited storage capacity or can work around that (Again, SSDs are working on this “con”)
• If you're recording music and don't want the scratchy sound from a hard drive intruding. Go for the quieter choice of SSDs
• If you want to reduce you electrical bills and want longer  battery life , go for SSD

HDDs are still the popular choice for the majority of average consumers, usually choosing the HDD as the storage option in their new computer simply due to the much cheaper cost. However, more and more consumers desire top computing performance and are opting for an SSD inside their new setup or as an upgrade to their current one. As such, SSDs are well on their way to becoming the mainstream, standard storage mechanism, especially for laptops given the advantages they present for a mobile device (they are currently the default storage device in the Ultra book category). That said, there will always be a market for both HDDs and SSDs. The advent of mSATA SSD devices and hybrid drives that include both SSD and HDD features is another option for consumers seeking a bit of the best of both worlds.

Hope you can figure out which type is the best choice for you now?