Useful information on hard disk and SSD drives
If a desktop or laptop PC doesn’t come with an SSD in one of its four main form factors shown at the top of this page – 2-5-inch, M.2, mSATA or PCIe – it must contains at least one internal hard disk drive (HDD) or SSHD, which is a combination of an HDD and an SSD as the permanent mass storage device for its operating system and software. The image above is of a standard HDD.
The new very thin, relatively expensive and light laptops have an SSD instead of a hard disk drive, which means that due to the higher cost of an SSD drive their data storage capacity is much less than most current standard laptops.
The image below shows a 2TB SSHD. Click on it to view its full size. You can install the operating system and games on the SSD part of the drive and applications and files on the HDD part. This makes the PC work as fast as an SSD.
SSDs have become very much cheaper since 2017
SSDs have become much cheaper since 2017. In January 2019, you could get a 500/1000GB 2.5-inch form factor drive for £60/£120.
SSDs that use an M.2 form-factor slot on the motherboards that provide them are relatively inexpensive. A 500GB/1TB M.2 SSD costs around £65/£120.
However, a 128GB mSATA form-factor SSD (£70 in Jan. 2019) costs about the same as a 500GB M.2 form-factor SSD. mSATA form factor SSDs are the most expensive by far.
Note that an internal 2.5-inch SSD uses the same serial SATA interface as a standard hard disk drive. Also note that, as with external hard disk drives, portable SSDs are available that use the USB interface.
SSD Form Factors: 2.5-inch, mSATA, M.2 –
The M.2 motherboard slot interface mostly used for SSDs
Most recent motherboards come with a M.2 (m-dot-2) slot. There is too much to know about this motherboard slot to put it on this page, so a good link is provided below instead. At some point I will write my own page on it. The main use of the slot is to provide an SSD as card that exceeds the speed of an SSD drive using the SATA interface. Wi-Fi cards for the slot are available.
Here is the essential information that you need to bear in mind when purchasing an M.2 SSD.
M.2 SSD Keying
“Currently an M.2 SSD has either one of three key types: B, M or B+M, while a socket can only have one key. As the key positions of B and M are slightly different, the M. SSD can only be installed one way.”
M.2 SSD Length – 2230- 2242 – 2260 – 2280 – 22110 (e.g., 2280 = 22mm wide and 80mm long.)
“As the M.2 standard requires the SSDs (or, other types: WiFi, Bluetooth etc) only have chips on the upward facing side, this means that greater capacity drives are usually longer since they require more storage (NAND) chips. Generally there are up to five lengths of M.2, however not every motherboard or notebook can accommodate them all.”
Buying An M.2 SSD? How To Tell Which Is Which – Provides illustrations of the different keying and lengths –
M.2 SSD installation
The image, below, from the user manual of an Asus motherboard, show how an M.2 SSD is fitted. The screw is removed, the card is inserted in the M.2 slot and is then screwed in. Note that the SSD has to support the M.2 slot. You can’t just buy an SSD and use the slot to install it.
“There’s a lot to unpack, starting with the fact that there’s more than one kind of M.2 connector, more than one type of interface that can be used with M.2, and more than one kind of M.2 card.” –
Understanding M.2, the interface that will speed up your next SSD –