access time

Thân thiện

A computer's hard drive has a fast access time for retrieving files.

Definition

1. Noun:
   • (Computing) The time interval between a request for data from a system and the moment that data is delivered from a storage device. This is a key performance metric for storage hardware, measuring the total delay a system experiences when reading or writing data. It is typically measured in milliseconds (ms) or nanoseconds (ns).

Usage

• Noun:
  • The primary use is to describe and compare the speed of computer memory and storage components.
  • It is often discussed in technical contexts involving hardware specifications, system performance, and optimization.

Examples

• Noun:
  • A solid-state drive (SSD) has a much faster access time than a traditional hard disk drive (HDD).
  • Reducing the memory's access time can significantly improve application performance.
  • The technical specification lists the average access time as 4.2 milliseconds.

Advanced Usage

• "Seek time": The time it takes for a storage device's read/write head to locate the correct track on a disk. This is one component of access time for mechanical drives.
• "Rotational latency": The delay waiting for the correct sector of a spinning disk to rotate under the read/write head. This is another component of access time for hard disk drives.
• "Command processing overhead": The time the drive's controller takes to interpret and initiate the read/write command.

Variants and Related Words

• Access (verb/noun): The general act of obtaining or retrieving data.
• Latency (noun): A broader term for any delay or wait time in a system, often used synonymously with access time in some contexts.
• Response time (noun): A related but broader term that can include network delays and software processing time, not just hardware access.

Synonyms

• Latency (in specific computing contexts).
• Response time (when referring specifically to storage hardware response).

Notes on Meaning

• In computing, access time is a precise technical term. It is not used in general language to describe waiting for entry or admission (e.g., "access time to the building").
• The definition explicitly states it is the sum of seek time, rotational latency, and command processing overhead. For solid-state storage (which has no moving parts), the seek time and rotational latency components are effectively zero, leaving primarily the command processing overhead and the time to read the memory cells.

Học thuật

Noun

1. (computer science) the interval between the time data is requested by the system and the time the data is provided by the drive
   • access time is the sum of seek time and rotational latency and command processing overhead