The SSD Glossary

The SSD Glossary

ACHI. SATA. RAID. What? If you've ever been confused by an SSD technical term, look no further. We've got you covered. In this user-friendly guide, our team of experts compiled a list of the most commonly used technical terms and sought to explain them in everyday words. The result? A guide that helps explain why SSDs do what they do and how they can improve your system's performance. Word by word, we'll make the technical more understandable.


Alignment refers to the partition alignment of a storage device. It determines the starting position of a partition to ensure optimal read/write performance. (For more information on partitions, see below.)
Basic input/output system. Often referred to as CMOS, the BIOS provides an interface for a computer's hardware and software. The BIOS determines how your hardware is accessed.
Binary digit. The smallest piece of data (a 1 or a 0) that a computer recognizes.
Buffers are holding areas for data shared by devices that operate at different speeds or have different priorities. A buffer allows a device to operate without the delays that other devices might impose.
Eight bits of information. The byte is the fundamental unit of computer processing; almost all specifications and measures of computer performance are in bytes or multiples thereof, such as Kilobytes (KB) and Megabytes (MB). Don't confuse byte (capital "B") with bit (lower case "b"). Bytes are capitalized becase they represent 8 bits of information; they're the larger unit of measurement.
A piece of very fast memory that's used to temporarily store ("place") data. On our website, you'll most likely find this term associated with the Crucial Adrenaline Solid State Cache Solution, which supplements your hard drive by caching ("placing") your most commonly used files on an SSD to dramatically increasing data access speeds.
Dataplex is the software that the Crucial Adrenaline uses for caching (see above). The software is provided by NVELO.
EZ Gig
Software that you can use to clone all of the content on your Windows-based hard drive and transfer it to an SSD. With the EZ Gig software, you don't need to reinstall your operating system and applications after an SSD upgrade. EZ Gig is designed to make the SSD upgrade process easy and user-friendly.
The File Allocation Table is like a rolodex for your computer - it tells your system where every file is located and how it can be accessed. FAT is widely used on storage devices like HDDs and SSDs, and it works with both Mac and PC systems. Newer versions of FAT include FAT16, FAT32 and exFAT.
File System
The file system determines how data is stored and accessed on a storage device. Common file systems include FAT and NTFS.
Form Factor
The physical size of the hardware components in your system. For example, the form factor for an SSD might be 2.5 inches or 1.8 inches, which tells you the dimensions of the SSD.
Formatting is a process where you prepare a storage device for use by configuring it with a file system. To do so, you have to delete any previous data on the drive.
Garbage Collection
Garbage Collection is a process that helps an SSD maintain optimal performance by freeing up memory sectors that are no longer in use. Garbage collection is part of the SSD itself and thus not dependent on your system's OS.
An interface is the means by which two independent systems communicate. A user interface (keyboard, mouse, etc.) allows you to communicate and connect with your system's OS. Likewise, another common interface is known as the software interface - the languages and codes that applications use to communicate with each other and the hardware. For SSDs, the interface refers to a connector that plugs your SSD into your computer so it can receive power or data.
Latency is the amount of time it takes for your system's memory to respond to a command. Generally speaking, the lower the delay (latency), the faster the device.
Logical Block Addressing is a method for specifying locations on computer storage devices.
Link Power Management is a SATA feature that reduces power to the SSD when your computer is turned off.
Multi-Level Cell (MLC) flash memory has two bits of data stored per memory cell, allowing four states of operation. This allows for greater capacities at lower cost (when compared to single-level cells) and makes MLC flash memory the ideal solution for consumer-based SSDs.
An mSATA is a micro-sized SSD that looks like a thin module - it's designed for thin notebooks (ultrabooks) like the MacBook Air. Like all other SSDs, it replaces the hard drive. (The unit itself is called an mSATA because it uses a low-profile or "mini SATA" interface.)
Mean time between failures - in other words, how long it takes between one data failure and the next on your HDD or SSD. Data failures occur far more frequently on HDDs than on SSDs.
NAND refers to flash memory, so think of it like your flash drive. When you pull the flash drive out of your computer, it retains any information that you stored on it. Flash memory (NAND) is what makes this happen. When you remove the power source, the flash memory retains its information. NAND is used in Crucial SSDs and in Lexar flash drives. Micron is one of the largest NAND manufactureres in the world.
Native Command Queuing (NCQ)
Native Command Queuing is a feature that allows SATA drives to optimize the order in which read/write commands are executed, increasing overall SSD performance gains.
The New Technology File System is the standard file system used in storage devices on Windows-based systems.
The OS is the operating system that your computer runs on, such as Windows or Mac OS. Windows XP and Windows 7 are examples of different operating systems.
Disk partitioning divides the space of a storage drive into separate data areas, known as partitions. Think of partitioning like a chest of drawers for your data. If your data is in a storage location - a drawer - then the partition is the wood that divides the drawers.
Parallel Advanced Technology Attachment - Is an older interface standard that connects legacy HDDs, CD/DVD drives, and floppy disk drives to your computer's motherboard—think of it like an umbilical cord because it allows data to flow between the two. PATA technology has largely been superceded by SATA technology.
Redundant Array of Independent Disks is a storage device feature that involves combining two or more storage drives to work as a single drive for better performance and security.
In computer terms, a "read" refers to accessing a piece of data from a storage device or memory.
Self-Monitoring, Analysis, and Reporting Technology (SMART) is a monitoring system for HDDs and SSDs that's designed to detect and report on various indicators of reliability and thereby anticipate (and avoid) system failures.
Serial Advanced Technology Attachment. It's a type of interface that connects a storage device or optical drive to your computer's motherboard—think of it like an umbilical cord because it allows data to flow between the two. SATA is measured by how fast data transfers to/from the device. There are three SATA speeds, SATA I (1.5Gb/s), SATA II (3.0Gb/s) and SATA III (6.0Gb/s).
Single-Level Cell (SLC) is a straightforward flash memory architecture that provides one bit of data stored per memory cell and two states of operation. This technology is commonly used in enterprise storage solutions.
There are two types of speed: frequency and bandwidth. Frequency refers to how many cycles the data can run per second, typically expressed in the number of MHz per second (1 MHz = 1 million cycles per second). Bandwidth refers to how much data can pump through the system's pipeline. Think of bandwidth like a drainage pipe. The bigger the pipe, the more water you can pour through at once. Bandwidth is generally expressed as the number of gigabytes per second that the system can process.
Solid state drives are the flash-based alternatives to traditional hard drives. Not only are they faster and more durable than traditional hard drives, they also offer faster boot times and they use less power. Unlike HDDs, SSDs have no moving parts so they are less prone to damage or component failure.
Storage refers to any device that you can save data to - an HDD, SSD, flash drive, CD, etc.
SuperDuper software allows you to clone your Mac HDD onto your new Crucial SSD among other things. It's designed for Mac OS only.
Swapping is when your system borrows some of the hard drive's memory when its RAM is fully in use. Swapping is also referred to as virtual memory.
These are units that measure the density of your storage device or memory. 1 Kilobyte (KB) equals 1024 Bytes. 1 Megabyte (MB) equals 1024 KB. 1 Gigabyte (GB) equals 1024MB and 1 Terabyte (TB) equals 1024 GB. Note the capital B for Bytes, not to be confused with Kb which is 1024 Kilo bits (8 times less than a KB).
A TRIM command allows your operating system to tell your SSD which data blocks are no longer in use so that they can be internally removed. This process helps increase overall SSD efficiency. It is the same as Garbage Collection only initiated by the OS.
Virtual Memory
Virtual memory is when your system borrows some of the hard drive's memory when its RAM is fully in use. Virtual memory is also referred to as swapping.
Wear Leveling
Wear Leveling ensures that all NAND cells on a flash-based device are used evenly, which prolongs the life of a memory card, flash drive, or SSD. How wear leveling works is that data is stored in a certain part of each cell and each cell has a limited life. When data is consistently accessed from the same cell (location), it gradually wears the cell out over time. Wear leveling technology allows data to be disperesed more evenly and thus avoid wearing the cells out.
In computer terms, "write" refers to how quickly a piece of data can be saved to a storage device (saving a document is an example of a write function).

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