Zero-copy is a technique used in computer systems to transfer data between applications or devices without the need to copy the data multiple times during the process. This method significantly enhances performance by minimizing memory usage and CPU cycles.

Typically, in traditional data transfer methods, data is copied from one location to another, such as from user space to kernel space, which adds unnecessary overhead. With zero-copy, data is transferred directly between buffers without intermediary copies. This reduces the overall time and resources required for the transfer, making it an ideal choice for high-performance applications like file systems, networking, and databases.

Zero-copy transfer allows large amounts of data to be moved efficiently, bypassing redundant memory allocations and directly accessing buffers.

Key advantages of zero-copy:

  • Reduced CPU usage and memory consumption
  • Faster data transfer speeds
  • Improved system responsiveness, especially under high load

Common implementations of zero-copy include:

  1. Memory-mapped files
  2. Direct I/O operations
  3. Kernel-bypass network protocols

Table of comparison:

Traditional Transfer Zero-Copy Transfer
Multiple memory copies Direct memory access
Higher CPU load Lower CPU utilization
Slower data transfer Faster throughput