Upgrading your memory can be confusing, especially with evolving technologies, increasing options on the shelf and numerous acronyms. At Crucial, we’re here to help. We want you to feel comfortable upgrading, building your own PC or even just understanding the specs of your current setup.
Not all solid state drives (SSDs) are the same since there are some key elements that determine compatibility, speed and price.
Each term relates to either a form factor, a communications protocol or an interface, but can be combined into different devices in different ways — a reason why this can be so confusing! By the end of this article, you will have a solid understanding of the differences and relative benefits of each and be able to choose the perfect upgrade for your system.
Understanding M.2 form factor
M.2 is a form factor specification introduced in 2012 and designed to replace the mSATA standard. The M.2 specification spells out the physical size and shape of the SSD card you can connect to your system. The M.2 form factor is designed to maximize PCB (printed circuit board) while minimizing the amount of space it takes up in a PC or laptop. Your motherboard will need to have an M.2 slot to install a compatible M.2 SSD.
What is a M.2 Solid State Drive?
M.2 solid state drives are designed to be faster and more compact than traditional hard drives, making them ideal for use in laptops and desktops where space is limited and speed is crucial. M.2 solid state drives mount directly to the motherboard (just like RAM), which means you don’t need any cables or mounting brackets.
The M.2 form factor is small and rectangular in shape, almost like a piece of gum. Sizes can vary, with possible widths of 12, 16, 22 or 30 millimeters, but are generally 22 millimeters wide. Lengths can also vary, coming in 16, 26, 30, 38, 42, 60, 80 or 110 millimeters. Motherboards will accommodate a variety of lengths for an M.2 module to allow for flexibility, while the width is more fixed.
When you buy an SSD like the Crucial T500, you may see something like "M.2 2280" in the title, which is a combination of its dimensions — 22mm and 80mm in length — helping you know what to buy.
M.2 SATA SSD vs. M.2 NVMe SSD
When comparing M.2 SATA SSDs to M.2 NVMe SSDs, it's essential to understand the underlying technology and how it impacts performance.
- M.2 SATA SSDs utilize the SATA (Serial Advanced Technology Attachment) interface, a widely used standard for storage devices. This interface, while an improvement over traditional hard drives, has its limitations. M.2 SATA SSDs can achieve speeds comparable to their 2.5-inch SATA counterparts, typically reaching around 550-600 MB/s for sequential read/write operations. While faster than HDDs, this speed is capped by the SATA interface's bandwidth.
- M.2 NVMe SSDs leverage the PCIe (Peripheral Component Interconnect Express) interface, designed specifically for solid state storage. PCIe offers significantly higher data transfer speeds compared to SATA that allows NVMe SSDs to achieve much faster performance. NVMe SSDs can often surpass 5000 MB/s for both read and write operations, with the Crucial T705 reaching 14,500 MB/s thanks to the high-speed PCIe lanes enabling rapid communication between the SSD and the rest of the system.
The performance gap between M.2 SATA SSDs and M.2 NVMe SSDs becomes evident in demanding tasks such as gaming, content creation and professional workloads. NVMe SSDs excel in scenarios where speed is paramount, offering quicker load times, faster file transfers and improved overall system responsiveness.
Understanding SATA interface
What is SATA?
SATA is a type of interface used to connect storage devices like hard drives and solid state drives to a computer. It replaced the older PATA (Parallel ATA) standard and offers benefits such as smaller cables, lower costs and faster data transfer speeds. SATA is widely used in both consumer and enterprise storage solutions due to its efficiency and reliability.
SATA technology is an older interface launched in 2003 that brought massive advancements to computing and memory storage. If you have a SATA interface, only a SATA SSD will work with your computer, such as the Crucial BX500.
SATA vs PCIe interfaces
Now that we know the M.2 form factor dictates what type of storage drive we can connect to, our next job is to understand SSD interfaces.
In general PC building terms, an interface connects two or more separate components to exchange data or information. The SATA and PCIe interfaces are physical connections that transmit data from storage to the computer.
SATA and PCIe aren't the only available interfaces for SSDs, although they are now the most common.
Understanding NVMe technology
What is NVMe?
NVMe (NVM Express™, or Non-Volatile Memory Express) is a communication protocol designed specifically to work with flash memory using the PCIe interface. NVMe was created to take advantage of the parallel nature of solid state drives.
NVMe SSDs combined with a PCIe interface create unrivaled read and write speeds. However, you can also get PCIe-compatible SSDs that are non-NVMe.
NVMe performance
Combining the NVMe SSD and the PCIe connection results in read and write speeds four times faster than a SATA interface/SSD.
NVMe complements the parallel structure of contemporary CPUs, platforms and applications. These structures allow for more commands to flow simultaneously. NVMe uses an optimized path to issue commands and complete input/output and supports parallel operation with up to 64,000 commands within a single I/O queue and 64,000 possible queues. Older protocols such as SATA are serial in nature, with a limited number of commands in a single queue.
Discover our range of NVMe SSDs, including the Crucial T500 2TB, 1TB and PCIe 5.0 SSDs.
Find out more about how to install NVMe PCIe SSDs.
Understanding PCIe interface
What is PCIe?
PCIe (Peripheral Component Interconnect Express) is a newer interface that features a smaller physical footprint, meaning it takes up less space in your computer. The real advantage of the PCIe interface over SATA is the ability to transmit data on up to four lanes, whereas SATA only has one. PCIe SSD read/write speeds increase even more than SATA when combined with an NVMe SSD.
NVMe vs SATA SSDs
One of the key reasons NVMe is faster when comparing NVMe to SATA is the use of multiple lanes for the PCIe connection. NVMe drives utilize four lanes of PCIe to allow for data transfer rates significantly higher than those of SATA drives, which only use a single lane. This multi-lane approach provides faster read and write speeds (seen in the table below) which means faster gameplay, smoother multitasking and a more responsive computer.
| Product | Sequential Read | Sequential Write |
|---|---|---|
| Crucial T710 PCIe Gen 5 NVME M.2 SSD | 14,900 MB/s | 13,800 MB/s |
| Crucial T705 PCIe Gen 5 NVME M.2 SSD | 14,500 MB/s | 12,700 MB/s |
| Crucial T700 PCIe Gen5 NVMe M.2 SSD | 12,400MB/s | 11,800MB/s |
| Crucial P510 PCIe Gen4 NVMe M.2 SSD | 11,000MB/s | 9,500MB/s |
| Crucial T500 PCIe Gen4 NVMe M.2 SSD | 7,400MB/s | 7,000MB/s |
| Crucial P3 Plus Gen4 PCIe M.2 2280SS | 5,000MB/s | 4,200MB/s |
All these enhancements come with another benefit: reduced power consumption. The combination of NVME, PCIe and a lack of moving parts in SSDs results in a quieter storage drive that sips power and extends the battery life of laptops, notebooks, and tablets.
For more information, visit our article on Why You Should Upgrade to an NVMe SSD.
What SSD should I get?
Compatibility with your computer is the most important factor in choosing an SSD interface. It can be challenging to tell the difference between PCIe and SATA connections if you look at the slot on the motherboard. Check your computer specifications to see which interface your computer supports.
To make choosing an SSD even easier, use the Crucial Upgrade Selector™ or System Scanner to find compatible parts.
If you have the option of multiple M.2 slots where at least one supports PCIe, it's worth considering your secondary slot for an SSD upgrade. When combined with an NVMe SSD, PCIe will result in faster read and write times.
Table of SSD types and features
Feature |
SATA SSD |
M.2 SATA SSD |
M.2 NVMe SSD |
PCIe SSD |
|---|---|---|---|---|
Form Factor |
2.5-inch |
M.2 |
M.2 |
PCIe Add-in Card |
Interface |
SATA |
SATA |
PCIe |
PCIe |
Protocol |
AHCI (older) |
AHCI |
NVMe |
NVMe |
Speed |
~550MB/s |
~550MB/s |
3,500+ MB/s |
3,500+ MB/s |
Glossary of terms used in this article
SATA (Serial Advanced Technology Attachment)
An interface standard for connecting storage drives (HDDs and SSDs) to a computer motherboard. SATA interfaces use cables to transfer data, with a maximum speed of 600 MB/s (SATA III).
AHCI (Advanced Host Controller Interface)
A technical standard that governs how SATA interfaces communicate with the operating system. Designed for spinning hard drives, it has been largely replaced by NVMe for SSDs.
HDD (Hard Disk Drive)
A storage device that uses magnetic platters and a spinning disk to store data. Slower than SSDs but offers high capacity at a lower cost.
SSD (Solid State Drive)
A storage device that uses flash memory chips instead of a spinning disk. SSDs are much faster, more durable and consume less power than HDDs.
NVMe (Non-Volatile Memory Express)
A protocol designed specifically for SSDs to maximize speed by using the PCIe interface instead of SATA. NVMe drives can reach speeds 10x faster than SATA SSDs.
PCIe (Peripheral Component Interconnect Express)
A high-speed interface used for expansion cards (such as GPUs and SSDs). NVMe SSDs use PCIe instead of SATA for significantly faster data transfer speeds.
M.2
A form factor for SSDs that are slim and stick-shaped, like a RAM module. M.2 drives can use either SATA or PCIe (NVMe) interfaces, depending on the model and motherboard support.
Interface
Defines how the drive connects and communicates with the rest of the computer. It includes both the physical connection and the data transfer protocol (e.g., SATA, PCIe).
Protocol
A set of rules for how data is transferred over an interface. For example, AHCI is the protocol for SATA, while NVMe is the protocol for PCIe-based SSDs.
Form factor
Refers to the physical shape and size of a device. Desktop HDDs are 3.5”. Laptop HDDs & SATA SSDs are 2.5”. M.2 SSDs are measured in millimeters (e.g., 2280 means 22mm wide, 80mm long).