SATA and M.2 Solid-State Drive FAQs

All your SSD questions answered

Kingston solid-state drives are the ideal performance upgrade for consumers and organizations alike. Available in a wide range of models and capacities, Kingston SSDs extend the lifecycle of PCs and provide improved speed, performance and reliability when compared to traditional hard drives.

Backed by a two-, three- or five-year warranty, free technical support and legendary Kingston® reliability, Kingston solid-state drives provide data security combined with future-proof performance for complete peace of mind.

If you have any questions about Kingston solid-state drives, read on for the answers. If your question isn’t covered here, please visit the product pages listed below or contact a Kingston representative.

Frequently Asked Questions

SSD 101

What is an SSD?

SSD is short for solid-state drive. An SSD is built using NAND Flash or DRAM memory chips in place of the platters and other mechanical mechanisms found in hard disk drives (HDDs).

How much faster is an SSD?

This is a difficult question to answer, as no two systems are the same and performance can be affected by the OS, any drivers loaded, applications in use, the speed and configuration of the processor and many other factors. Several test web sites and magazines have tested SSDs against HDDs and found SSDs to be much faster. For example, if we compared random read performance, SSDs are more than 20000% faster than high-performance HDDs.

It is worth noting that SSD drives are not affected by the physical limitations of hard drives. HDD platters are circular in design (like a CD) and data held at the centre of the circle is accessed at a slower rate than data on the edges. SSDs have a uniform access time across the entire drive. HDD performance also suffers from data fragmentation, whereas SSDs performance is not significantly impacted even if the data is not stored contiguously.

What are IOPS?

IOPS (Input/output Operations per Second) is the unit of measurement to show the number of transactions per second a storage device (HDD or SSD) is capable of handling. IOPS should not be confused with read/write speeds and pertain to server workloads.

What does wear-levelling mean? Is it important?

SSD drives use NAND Flash memory as the storage medium. One of the disadvantages of NAND Flash is that Flash cells will eventually wear out. To extend the memory’s useable life, the SSD’s memory controller employs various algorithms that spread the storage of data across all memory cells. This prevents any one cell or group of cells from being “over used.” The use of wear-levelling technology is widespread and is very effective.

Why does my SSD have less capacity than some others?

To increase performance and endurance, some SSD manufacturers will reserve some of the drive capacity from the user area and dedicate it to the controller. This practice is known as over-provisioning (OP) and will increase the performance and longevity of the SSD. All current Kingston SSDs feature over-provisioning, and the capacities are 120GB, 240GB, 480GB, 960GB, 1.92TB and 3.84TB. Learn more about over-provisioning

Will my SSD wear out or lose performance the longer I use it?

The NAND Flash used in USB, SD cards and SSDs all have endurance limits meaning one cannot continue to write to them forever. Flash based products will eventually wear out however with features like wear-levelling and over-provisioning an SSD will typically last longer than the system it was installed into. We measure drive endurance in TBW (Terabytes Written) and depending on drive capacity one can write hundreds of terabytes, up to petabytes. Performance of the SSD will remain the same throughout the life of the drive. Learn more about TBW.

What are SMART attributes?

S.M.A.R.T. stands for Self-Monitoring, Analysis, and Reporting Technology and is a part of the ATA standard. SMART attributes are used to measure drive “health” and enabled to warn the user (administrator, software program, etc.) of impending drive failure. Learn more about S.M.A.R.T.

Can an SSD be used in an external enclosure via USB or e-SATA?

Yes. Kingston SSDs can be used in USB, e-SATA, Thunderbolt and Firewire external enclosures. Note if the user chooses to enable a password via the ATA Security command, the drive will not be accessible via external enclosure.

SSD vs HDD

What is the difference?

HDDs are based on magnetic spinning platters, a technology that has been in use since the mid- 1950s. The data is written to and read from these spinning platters or disks via moving heads. HDDs are mechanical devices with many moving parts and are more prone to mechanical failures and failures due to environmental conditions such as heat, cold, shock and vibration.

Why do SSDs cost more than HDDs?

Although the SSD market is growing and gaining more popularity, it is still relatively new. As with any new technology, it is only a matter of time before sales increase to a level that will allow manufacturing costs to reduce. In the last few years, the price gap between SSD and HDDs has gotten much smaller.

Are there any trade-offs when choosing an SSD over an HDD?

The only factor in favor of HDDs is the price per Gigabyte. HDDs are currently sold in capacities of 500GB and above, while SSDs are sold in capacities of 120GB and above. Kingston currently offers SSDs from 120GB to 3.84TB.

Traditional HDDs are best if mass storage is in the Terabytes is your primary need, while SSDs are excellent if performance is more important. It’s common to use an SSD as a boot drive to hold OS and applications and an HDD to hold data files..

Can I transfer data or OS from an existing HDD to a new SSD?

Yes. Kingston offers SSD drives in upgrade kits that include all the necessary items required to replace a notebook or desktop HDD with a Kingston SSD, including software to easily transfer the OS and important data. Please note that SSD-only SKUs do not include the software. If you need to clone your HDD to a new SSD you will need the bundle kit.

Does an SSD require defragmenting like an HDD?

No. SSDs never need to be defragmented. Defragmenting an SSD can reduce the life of an SSD. If your system is set up to defragment automatically, you should disable or turn off defragmentation when using an SSD. Some operating systems will defragment automatically, so this feature should be disabled for Kingston SSDs.

M.2 SSDs explained

What is M.2? Is it the same as NGFF?

M.2 was developed by the PCI-SIG and SATA-IO standards organizations and is defined in the PCI-SIG M.2 and the SATA Rev. 3.2 specifications. It was originally called the Next Generation Form Factor (NGFF), and then formally renamed to M.2 in 2013. Many people still refer to M.2 as NGFF.

The M.2 small form factor applies to many add-in card types, such as Wi-Fi, Bluetooth, satellite navigation, Near Field Communication (NFC), digital radio, Wireless Gigabit Alliance (WiGig), Wireless WAN (WWAN), and Solid-State Drives (SSDs).

M.2 has a subset of specific form factors strictly for SSDs.

Why would I want to install it?

All M.2 SSDs flush-mount into M.2 sockets on system boards. The M.2 form factor introduces a path to higher performance via a smaller footprint and is the future path for SSD technological advancement. In addition, no power or data cables are needed, making cable management unnecessary. Like mSATA SSDs, M.2 SSDs just plug into a socket and the physical installation is complete.

What are single-sided and double-sided?

For certain embedded applications where space is limited, the M.2 specifications provide for different thicknesses of M.2 SSDs – 3 different single-sided versions (S1, S2 and S3) and 5 dual-sided versions (D1, D2, D3, D4 and D5). Some platforms may have specific requirements due to limited space below their M.2 connector.

Main System Board

Kingston M.2 SSDs conform to the dual-sided M.2 specifications and will fit in the majority of system boards that accept dual-sided M.2 SSDs; please consult with your sales representative if you require single-sided SSDs for specific embedded applications.

What systems does it work in?

There are many notebooks and motherboards that support the M.2 SSD. Please consult your system-specifications and user manual to check for compatibility before purchasing an M.2 SSD.

What are the different M.2 SSD dimensions?

For SSD-based M.2 modules, the most common sizes are 22mm wide x30mm long, 22mm x 42mm, 22mm x 60mm, 22mm x 80mm and 22mm x 110mm. The cards are referred to using the above dimensions: the first 2 digits define the width (all 22mm) and the remaining digits define the length, from 30mm to 110mm. So, the M.2 SSDs are specified as 2230, 2242, 2260, 2280 and 22110.

The picture below shows a 2.5-inch SSD and a 2242, 2260 and 2280 M.2 SSDs:

Size range image

Why are there different lengths?

There are 2 reasons for the different lengths:

  1. The different lengths enable different SSD drive capacities; the longer the drive, the more NAND Flash chips can be mounted on it, in addition to a controller and possibly a DRAM memory chip. The 2230 and 2242 lengths support 1-3 NAND Flash chips while the 2280 and 22110 support up to 8 NAND Flash chips, which can enable a 2TB SSD in the largest M.2 form factor.
  2. Socket space in the system board can limit the M.2 size: Some notebooks can support an M.2 for caching purposes, but offer a small space that will accommodate only a 2242 M.2 SSD (2230 M.2 SSDs are smaller still but not needed in most cases where 2242 M.2 SSDs will fit).
Is an M.2 SSD the same as an mSATA SSD?

No, they are different. M.2 supports both SATA and PCIe storage interface options, while mSATA is SATA only. Physically, they look different and cannot be plugged into the same system connectors.

Module image

M.2 2280 (above) compared to mSATA. Note the keys (or notches) that will prevent them from being inserted into incompatible sockets.

Why was it created?

The M.2 form factor was created to provide multiple options for small-form-factor cards, including SSDs. SSDs previously relied on mSATA for the smallest form factor, but mSATA was unable to be scaled up to 1TB capacities at a reasonable cost. The answer was the new M.2 specification that allows for different M.2 SSD card sizes and capacities. The M.2 specification allows system manufacturers to standardise on a common small form factor that can be extended to high capacities where needed.

Do I need a special driver to use M.2 SSDs?

No, both SATA and PCIe M.2 SSDs will use the standard AHCI drivers built into the OS. However, you may need to enable the M.2 SSD in the system BIOS before being able to use it.

Why would I need to enable my M.2 SSD within the BIOS?

In certain cases, the M.2 SSD socket could share PCIe lanes or SATA ports with other devices on the motherboard. Please review your motherboard documentation for additional information as using both shared ports at the same time could disable one of the devices.

What do the different module keys mean?

The M.2 specification defines 12 keys or notches in the M.2 card and socket interface; many are reserved for future use:

table

Specifically, for M.2 SSDs, there are 3 commonly used keys:

  1. B-key edge connector can support SATA and/or PCIe protocol depending on your device but can only support up to PCIe x2 performance (1000MB/s) on the PCIe bus.
  2. M-key edge connector can support SATA and/or PCIe protocol depending on your device and can support up to PCIe x4 performance (2000MB/s) on the PCIe bus, provided that the host system also supports x4.
  3. B+M-key edge connector can support SATA and/or PCIe protocol depending on your device but can only support up to x2 performance on the PCIe bus.

The different key types are often labelled on or near the edge connector (or gold fingers) of the M.2 SSD and also on the M.2 socket.

Key image

Note that B-keyed M.2 SSDs have a different number of pins at the edge (6) compared to M-keyed M.2 SSDs (5); this asymmetrical layout prevents users from reversing the M.2 SSDs and attempting to plug a B-keyed M.2 SSD into an M-keyed socket, and vice versa.

What is the benefit of having both B+M key?

The B+M keys on an M.2 SSD allow for cross-compatibility on various motherboards if the appropriate SSDs protocol is supported (SATA or PCIe). Some motherboard host connectors may be designed only to accommodate M-key SSDs, while others may only accommodate B-key SSD. The B+M keys SSD was designed to address this issue. However, plugging an M.2 SSD into a socket will not guarantee it will work, as that will depend on having a shared protocol between the M.2 SSD and the motherboard.

How do I know which length M.2 SSDs my motherboard supports?

You should always read the motherboard/system manufacturer’s information to confirm which lengths are supported, but many motherboards will support 2260, 2280 and 22110. Many motherboards will provide a multiple retaining-screw offset, allowing a user to secure either a 2242, 2260, 2280 or even up to 22100 M.2 SSD. The amount of space on the motherboard will limit the size of M.2 SSDs that can be secured into the socket and used.

When “socket 1, 2 or 3” is referenced, what does that mean?

Different socket types are part of the M.2 specification that requires support for specific device types within a given socket.

Socket 1 is designed for Wi-Fi, Bluetooth®, NFC and WI Gig

Socket 2 is designed for WWAN, SSD (caching) and GNSS

Socket 3 is designed for SSDs (both SATA and PCIe, up to x4 performance)

Are M.2 SSDs hot-pluggable?

No, M.2 SSDs were not designed to be hot-pluggable. Please install and remove M.2 SSDs when the system is powered off.

M.2 SATA SSD vs M.2 PCIe SSD

Are M.2 SATA SSDs faster than standard 2.5-inch SATA or mSATA SSDs?

Performance would likely be similar; it would also depend on the specific controller inside the host system that the SSDs were using as well as the internal layout and controller of each SSD. The SATA 3.0 specification supports up to 600MB/s whether in a 2.5”, mSATA or M.2 SSD form factors.

What would happen if I connect a PCIe M.2 SSD to an SATA-only M.2 port or vice versa?

If the host system doesn’t support the PCIe protocol, the PCIe M.2 SSD will most likely not be seen by the BIOS and therefore would be incompatible with the system. Similarly, with a SATA M.2 SSD installed into a socket supporting PCIe M.2 SSDs only, the SATA M.2 SSD would not be usable.

What would happen if I connect a PCIe x4 M.2 SSD to a port that supports only PCIe x2 speeds?

The PCIe M.2 SSD would only be able to operate at PCIe x2 (2-lane functionality) speeds within that motherboard. If you purchase a motherboard that supports PCIe x4 speeds, your x4-capable M.2 SSD should work as expected within that environment. In addition, there are PCIe limitations on system boards where the total number of PCIe lanes could be exceeded, limiting the PCIe M.2 x4 SSD to either have 2 lanes or even none.

What is the difference?

M.2 is the physical form factor. SATA and PCIe refer to the storage interface, the primary difference is performance and the protocol (language) spoken by the M.2 SSD.

The M.2 spec was designed to accommodate both a SATA and PCIe interface for SSDs. M.2 SATA SSDs will use the same controller currently on a typical 2.5” SATA SSDs. M.2 PCIe SSDs will use a controller specifically designed to support the PCIe protocol. An M.2 SSD can only support one protocol, but some systems have M.2 sockets that can support either SATA or PCIe.

Does an M.2 SSD support both SATA and PCIe?

No. An M.2 SSD will support either SATA or PCIe, but not both at the same time. In addition, system board sockets will be designated by manufacturers to support either SATA, PCIe, or in some cases, both. It is important to check your system’s manual to verify which technologies are supported.

Are M.2 PCIe SSDs faster than M.2 SATA?

The PCIe interface is faster, as the SATA 3.0 spec is limited to ~600MB/s maximum speed, while PCIe Gen 2 x2 lanes is capable of up to 1000MB/s, Gen 2 x4 lanes is capable of up to 2000MB/s, and Gen 3 x4 lanes of up to 4000MB/s.

Kingston SSDs – Everything you need to know

Are Kingston SSDs built using NAND Flash or DRAM Memory?

Kingston SSDs are built using NAND Flash Memory.

What Operating Systems (OS) are supported?

Kingston SSDs are OS independent and will run on any system supporting a standard SATA interface.

Do Kingston SSDs require any special drivers?

No additional drivers are required.

Can a Kingston SSD be used in any system?

Kingston SSDs can be user-installed in any system that supports the SATA II or III interface. (SATA 3Gb/sec. and 6Gb/s)

Can Kingston SSDs be used for RAID?

• Yes, the A, E, DC, KC, HyperX, S, V and UV Series SSDs can be used in RAID configurations; however, Kingston recommends using the E and DC Series SSD for RAIDs on servers. Learn more about RAID.

Can Kingston SSDs be connected to SAS-based systems?

It is very common that SAS (Serial Attached SCSI) based systems and controllers also support SATA devices. Kingston recommends that users check with the system or controller documentation to make sure that both SATA and SAS drives are compatible. If they are, Kingston SSDs may be successfully used.

Do Kingston SSDs use Garbage Collection?

All Kingston SSDs use an intelligent and efficient garbage collection process that improves drive life with little impact on Flash endurance and is invisible to the user. Learn more about SSD garbage collection.

Do Kingston SSDs employ wear-levelling?

Kingston SSDs integrate advanced wear-levelling techniques that incorporate a block picking algorithm capable of extending flash endurance and optimizing drive life. This unique wear-levelling ensures that the individual Flash memory blocks are consumed at a very balanced rate, not to exceed a 2% difference between the most often written blocks and least written.