Hard drive guide


It’s where all the data in your computer is stored for the long term — not just the things you save, but all the code required for your operating system, the framework browsers use to connect to the internet, drivers for your accessories, and everything else. When people talk about computer storage, they are talking about the hard drive.
The hard drive is sometimes referred to as the "C drive" due to the fact that Microsoft Windows, by default, designates the "C" drive letter to the primary partition on the primary hard drive in a computer. While this is not a technically correct term to use, it is still being used - and understood by PCS staff.

Which one should I get?
In regards to speed and general performance it would be M.2 SSD > SSD > SSHD > HDD.
In regards to price and capacity it would be HDD > SSHD > SSD > M.2 SSD.

As so many other things in life, this decision has to be a balance between price and usage. I would always recommend to first take a look at how much storage is really needed and then go with the fastest hard drive that is financially possible. Keep in mind that your basic software, like the OS (Windows) take up some space, too. Windows is said to be roughly around 30GB- 40GB.
If you have a lot of photos/music: For example, 250GB can hold more than 30,000 average size photos or songs. MP3 files come in at around 5MB, which varies either way depending on the length of the song. If we take that 5MB figure, you’ll be able to fit just over 200 files within 1GB of space.
If you have a lot of movies: For Amazon movies, an SD movie coming in at two hours or two two-hour episodes of a show in SD will set you back around 1.5GB. If you use a 250GB hard drive and assume 50GB is taken up by OS and software, you can fit about 130 movies or 260 one-hour episodes on it before you run out of space.
If you have a, lot of games: For most Gamers a capacity of 500GB up to 1TB is considered more than enough. There are lots of enjoyable games that are pretty small, but then you get games that are 60, 100, even 150 GB – especially with 4k Resolution and AddOns.

The different types:

HDD Hard Disk Drive
It uses a magnetic disk that can hold information inscribed in very tiny tracks ( a bit like a record player). This requires moving parts, specifically heads to read and write data to the disk as needed, and propulsion to spin the disk. A hard drive is usually the size of a paperback book, but much heavier. The hard drive is normally mounted in the 3.5-inch drive bay in the computer case. The back end of the hard drive contains a port for a so-called SATA cable that connects to the motherboard. Also here is a connection for power from the power supply.

Noise: HDDs have moving parts (heads, actuator, and spindle motor) and make characteristic sounds of whirring and clicking; noise levels vary between models, but can be significant (while often much lower than the sound from the cooling fans).
Speed: It is measured in RPM "revolutions per minute". A standard hard drive has a spinning disc inside of it - RPM measures how many times that disc spins in a minute. So you basically want that number to be as high as possible.
Reliability and lifetime: 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. If kept in a dry environment at low temperature, HDDs can retain their data for a very long period of time even without power. However, the mechanical parts tend to become clotted over time and the drive fails to spin up after a few years in storage.
Key feature: High Capacity for a small price and versatile storage

SSHD Solid State Hybrid Drive
It's a traditional hard disk with a small amount of solid-state storage built in, typically 8GB or so. The drive appears as a single device to Windows (or any other operating system), and a controller chip decides which data is stored on the SSD and what's left on the HDD. Seagate's SSHDs intelligently learn which applications you use most, and try to store those in the solid-state storage for faster loading times and better overall performance – meaning, it will be faster the more you use it. If files aren't used repeatedly, the solid state cache benefit is not remarkable.
In terms of capacity ratings, the SSHD does cost slightly more than a traditional hard drive because of the addition of the more expensive solid-state cache memory and additional firmware to control the caching processor.
The SSHD is far cheaper than a full solid state drive. For the capacities, an SSD will cost anywhere from five to about twenty times the cost of an SSHD.

Noise: Like a traditional HDD, as the SSHD has moving parts as well.
Speed: With the SSD Cache on top of the HDD mechanics within an SSHD, it can reach a boost when used with the same files over and over again. The cache will start to provide reoccuring files faster, the more you use said files. More numbers on 500GB, 1TB and 2TB Seagate Firecudas: https://www.seagate.com/gb/en/internal-hard-drives/hdd/firecuda/#2-5-inch-specs (Click on the red Data Sheet symbol)

Reliability and lifetime: SSDs are supposed to retain data for about ten years. FireCuda Flash Accelerated drives are backed by an industry-best 5-year limited warranty.
Key Features: Faster Boot times (roughly 5 times faster than a traditional HDD) and a good price for acceptable capacity

SSD Solid State Drive
If you are looking at a modern laptop, you will likely see that most come equipped with a solid-state drive. This form of computer storage has been on the market for some time but only recently has been embraced by the industry (and consumers). Solid state is a term that refers to electronic circuitry that is built entirely out of semiconductors. There are no moving parts here: Instead, these hard drives use semiconductors that store information by changing the electrical state of very tiny capacitors.
SSDs on the outside look almost identical to a traditional hard drive. It also uses the common SATA interface so that it can easily be placed into any PC as a hard drive would.

Noise: SSDs have no moving parts and therefore are basically silent, although on some SSDs, high pitch noise from the high voltage generator (for erasing blocks) may occur.
Speed: In an SSD speed is measured through mb/r (read)and mb/w (write). In consumer products the maximum transfer rate typically ranges from about 200 MB/s to 2500 MB/s, depending on the drive. The higher the number, the faster the data transfer.
Reliability and lifetime: 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. If left without power, worn out SSDs typically start to lose data after about one to two years in storage, depending on temperature. New drives are supposed to retain data for about ten years.
Key Features: Faster Boot times (roughly 5 times faster than a traditional HDD) and a good price for acceptable capacity

An M.2 SSD is a solid-state drive (SSD) that conforms to a computer industry specification written for internally mounted storage expansion cards of a small form factor. The specification, originally known as the Next-Generation Form Factor (NGFF), is pronounced M-dot-2.
M.2 and mSATA cards are different form factors and have different connectors, they cannot be plugged into the same devices. M.2 SSDs are faster and store more data than most “normal” SSDs. AS these hard drives are plugged into specific M.2 slots on the motherboard, this component determines if and how many M.2’s you can have in your system. In most laptops it is one, in some desktop motherboards it’s two. There is a specific card to use up to six M.2 together, but PCS doesn’t install or supports that. Upgrading to an M.2 drive or accessory requires therefore a little forethought.
As far as prices... M.2 drives are still fairly cutting edge in the consumer market, so even on events like Black Friday you aren't going to be seeing much of a price drop.

Noise: None.
Speed: Like SSDs, the speed of M.2 SSDs are measured through mb/r (read)and mb/w (write). The higher the number, the faster the data transfer.
Reliability and lifetime: M.2 SSDs are pretty safe from bumps and drops, as they are installed directly in the motherboard. Samsung even offers a warranty up to 1,200 TBW with a 5-year limited warranty on their 970 Evo.
Key Features: The crème de la crème when it comes to speed (and price).
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Multiverse Poster
I'll just beat everyone else to the punch and say that consensus on the forums (and from what I can tell, the entire internet other than Seagate who make and sell SSHDs) is that SSHDs are not worth it.

SSDs are now so inexpensive that it is almost always better value to get an HDD for mass storage, and an SSD for Windows, programs, and favourite games. Instead of spending £30 more than an HDD on an SSHD.

It's also worth taking claims of "Application Load Test: 300% Faster" with a grain or few of salt. These are stats proferred by Seagate, whose business is to sell SSHDs... It is worth checking out reviews by 3rd parties for more realistic ideas of what to expect e.g.
i.e. sometimes a laptop SSHD will load games slower than a 7200rpm drive, and when an SSHD is faster, '300% faster' is.. not what you might typically expect in the real world. Let's put it that way :)


Prolific Poster
I absolutely second this.

Also - you don't see SSHD used in enterprise environments.

You get tiered storage which is SSD down to SATA with the likes of fibre channel and SAS of varying speeds (up to 15k) in the mix.

SSD is obviously the fastest tier and SATA is generally used for near-time storage - i.e. data is moved there before being finally backed up to tape. This is because you can get super-high capacity SATA drives but they're not fast, in enterprise terms, but are much faster than getting off of a tape.

I could see the point, kind of, when SSD was still hideously expensive but I got an email today from Amazon with a 960GB SATA SSD (ok...not the fastest type by far, but miles faster than SSHD or HDD) for around £140 and the 240GB ones for a bout 35/40 quid.


The BSOD Doctor
It's worth mentioning that an average HDD has a data transfer time of about 150MB/s (although it varies a little from vendor to vendor and even disk to disk), this helps compare with the data transfer speed of SSDs. What makes HDDs so much slower is the time taken to move the read/write heads, this is called seek time and is measured in milliseconds. Vendors usually quote an average seek time and this is usually the time taken to seek (move the read/write heads) one-third of the way across the disk - a typical average seek time is about 10ms. In addition it's necessary to wait for the wanted data to rotate under the read/write head, this is called latency and it is a fixed value based on the rotational speed of the disk. Vendors usually quote an average latency and is the time for the disk to make half a revolution, for a 5400rpm disk it's 5.6ms and for a 7200rpm disk it's 4.2ms. Thus, very roughly, on average it's going to take about 14.2ms on a 7200rpm disk just to position the read/write heads over the wanted data - and that's before you've moved even a single byte of data.

Regarding SSHDs, the key here is the algorithm that manages the cache (the built-in solid state storage). If the disk is serving only one purpose (as a Windows system drive for example) then the most regularly used data is likely to stay in the cache and this improves performance. However, if an SSHD is used for multiple purposes (as a Windows system drive AND a user data drive) then the different access patterns to the different kinds of data will tend to pollute the cache so that it's not able to tell which is the most regularly used data and you don't get the expected performance benefit. There are several posts on here of people complaining about the poor performance of Seagate SSHDs when used as a mixed system and data drive. In addition, high disk activity apps (like Windows Update) also tend to pollute the cache and can make system performance pretty poor - several posters have complained about the detrimental effect of Windows Update on SSHD performance. Personally I think they can work quite well as a pure data drive, but I would not advise using an SSHD as the only drive in any computer.
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We love you Ukraine
None of the figures in Seagate sales info are based on any kind of real world usage scenario, they’re just total garbage.


Prolific Poster
None of the figures in Seagate sales info are based on any kind of real world usage scenario, they’re just total garbage.

I imagine they did someting akin to VW and their emissions tests - read/wrote the same file / files that just fit into the cache, possibly optimised to make the best use of it.


The BSOD Doctor
None of the figures in Seagate sales info are based on any kind of real world usage scenario, they’re just total garbage.

I imagine they did someting akin to VW and their emissions tests - read/wrote the same file / files that just fit into the cache, possibly optimised to make the best use of it.

I rather suspect that they are based on some testing, but done in the most advantageous way with data patters that benefit the cache algorithms. I would think that they represent the absolute best that can be achieved, but I seriously doubt that they are indicative of what can be expected in the real world.

Stephen M

Author Level
I fail to understand why Seagate are still trying to push this garbage. Their drives are decent, nearly all my external back up drives are Seagate and have never had a problem with them. I suppose the hybrids must sell quite well so it is just a profit thing for Seagate, it is certainly not something to try to boost the image of the company.