Which of the following is true for SSD?

Solid State Drives, commonly known as SSDs, have become increasingly popular in computers over the past decade. As the name suggests, SSDs utilize solid state memory rather than mechanical spinning platters to store data. This leads to some key differences in performance and other characteristics compared to traditional hard disk drives (HDDs). In this article, we will explore some of the major aspects of SSDs and look at which of the following statements are true.

SSDs have no moving parts

This is true. A key difference between HDDs and SSDs is that SSDs do not contain any moving parts. HDDs rely on platters that physically spin along with read/write heads that move to access data on different parts of the platters. The mechanical nature of HDDs leads to certain limitations in speed, stability, and reliability.

SSDs on the other hand utilize NAND flash memory chips to store data. These chips have no moving parts, allowing SSDs to operate silently and withstand more physical shock compared to HDDs. The lack of moving parts also allows SSDs to access data faster since they do not have to mechanically seek to different locations on a platter.

SSDs are more expensive than HDDs per gigabyte

This is generally true. SSDs currently cost more per gigabyte than HDDs. As of 2022, a typical SSD might cost around $0.20 per gigabyte while a typical hard drive costs around $0.03 per gigabyte. There are a few reasons for the higher cost of SSD storage:

  • Manufacturing costs: Producing NAND flash memory is more complex and expensive than producing traditional magnetic storage platters.
  • Capacity limitations: SSD capacities remain lower than HDDs, and the cost per gigabyte tends to increase at higher capacities.
  • Newer technology: SSDs are a newer technology compared to HDDs and economies of scale have further matured for hard drives.

Over time, SSD prices have steadily declined and this trend is likely to continue. However, HDDs remain significantly cheaper per gigabyte due to the mechanical simplicity of the technology.

SSDs provide faster access to data than HDDs

This is absolutely true. One of the biggest benefits of SSDs over HDDs is the dramatically faster access to stored data. Let’s examine read/write speeds to see the difference:

Drive Type Typical Read Speed Typical Write Speed
HDD (magnetic drive) 80-160 MB/s 80-160 MB/s
SSD (NAND flash) 500+ MB/s 200-500 MB/s

As you can see, SSDs offer between 3-5x faster read speeds and up to 5x faster write speeds compared to HDDs. This substantial performance advantage is enabled by the lack of moving parts and the direct electrical access of stored data on SSDs.

Faster access speeds allow SSDs to boot operating systems, load programs, and open files much quicker than HDDs. For tasks like gaming, video editing, databases and any disk intensive operations, SSDs provide a significant boost.

SSDs have higher IOPS than HDDs

This statement is true. IOPS stands for Input/Output Operations Per Second. This measures how many read and write operations a drive can perform in one second. Just like sequential access speeds, SSDs deliver far higher IOPS than HDDs due to their faster access of stored data.

A typical consumer-grade hard drive might offer 100-200 IOPS. On the other hand, even budget SSDs start around 10,000 IOPS while high performance models can exceed 100,000 or even 1 million IOPS. This big difference in IOPS once again makes SSDs much faster for random access patterns that involve many small file operations.

SSDs have lower latency than HDDs

This is definitely true. Latency refers to the delay between a request for data and when the data is actually delivered from the drive. SSDs inherently have much lower latency due to not having to mechanically move drive heads to access data.

For HDDs, latency is generally in the range of 5-10 milliseconds (ms). SSDs can reach latency under 0.1 ms for reading data and around 0.2 ms when writing. This sub-millisecond latency gives SSDs a very responsive feel compared to the higher lag of HDDs.

SSDs are lighter and smaller than HDDs in physical size

This is generally true when comparing SSDs and HDDs of the same capacity. Let’s look at some examples:

  • 2.5″ SATA SSD: 2.75 x 3.96 x 0.28 inches, 1.76 ounces
  • 2.5″ HDD: 2.75 x 3.96 x 0.59 inches, 3.52 ounces

For the common 2.5″ form factor, SSDs are less than half the thickness of HDDs and about 50% lighter. This compact design makes SSDs well-suited for ultra thin laptops and mobile devices where HDDs would have difficulty fitting.

However, higher capacity 3.5″ HDDs can get much larger and bulkier than SSDs. So for very high storage needs, SSDs maintain the advantage of smaller physical size and less weight.

SSDs have faster boot and load times for operating systems and games

Absolutely true. The dramatically faster data access speeds of SSDs directly translate into much quicker boot ups and load times for operating systems, games, and software. Let’s compare some numbers:

OS/Game HDD Load Time SSD Load Time
Windows 10 Boot 45-90 seconds 15-30 seconds
The Witcher 3 Level Load 50-60 seconds 10-15 seconds

As you can see, switching from an HDD to SSD can cut boot and load times by 50-70%. For users who frequently shut down and startup their computers or who play games with many load screens, this difference quickly adds up to significantly improved responsiveness and less waiting around.

SSDs have no defragmentation requirements

This statement is true. Defragmentation is process in HDDs where data is reorganized to be sequentially written in order to boost performance. Due to the mechanical nature of HDDs, data can become fragmented in different locations on the drive platters. Defragmentation helps consolidate this so head seeking is minimized.

SSDs read and write data electronically across many NAND flash chips simultaneously. This means data locations do not impact performance, so defragmentation is not necessary. Operating systems will still perform minimal optimization routines on SSDs, but there is no need for the full defragmentation process required by HDDs.

SSDs have faster sustained write speeds than HDDs

This is sometimes true but not always. HDDs and SSDs handle sustained writes – continually writing data to the drive over an extended period of time – differently. For HDDs, sustained write speeds will remain fairly consistent over time. However, for some SSDs write speeds can drop significantly after writing a large amount of data.

This is because SSDs need to erase existing data blocks before writing new data. If the drive is full and these erase operations can’t keep up, write speeds will throttle. However, SSD manufacturers have engineered solutions like overprovisioning spare capacity and advanced controllers to minimize this issue. So many modern SSDs can sustain high write performance similar to HDDs.

SSDs have higher mean time between failures (MTBF) than HDDs

This was historically true when SSDs first emerged but is no longer always the case with modern drives. MTBF is a reliability metric that provides the average expected lifetime between failures for hardware. Early SSDs offered a clear reliability advantage with a huge lead in MTBF over HDDs.

However, modern HDDs have closed this gap considerably through design improvements. High quality HDDs now offer over 1 million hour MTBF similar to top SSD models. Cheaper HDDs still have lower MTBF ratings around 300,000-500,000 hours while budget SSDs are in this range too.

Overall, the MTBF advantage of SSDs has diminished to the point where it is dependent on the specific drive models being compared rather than the underlying technologies.

SSDs are silent while HDDs emit audible noise

This is absolutely true. One of the immediately noticeable differences when using an SSD versus an HDD is the lack of audible noise. HDDs require spinning platters and moving heads that create very noticeable mechanical sounds during operation – seeking, spinups, etc.

SSDs have no moving parts, so they operate completely silent. The only sound emitted would be from an SSD’s electronics and cooling fans in its enclosure, both of which are very quiet compared to HDD noise. This makes SSDs preferable for quiet computing environments.


We’ve examined a variety of statements comparing Solid State Drives and Hard Disk Drives. In summary:

  • SSDs have superior performance – faster access speeds, IOPS, latency, boot/load times
  • SSDs are physically smaller, lighter, and silent
  • SSDs have different maintenance needs – no defragging required
  • SSDs are more expensive per gigabyte but prices are dropping
  • Reliability differences have largely evened out between quality SSDs and HDDs

For the majority of PC users today, an SSD is recommended as the primary storage drive for the operating system and applications. HDDs are still great for bulk data storage and backups, but the speed and responsiveness benefits of SSDs for everyday tasks makes them the superior choice.