diskstreaming

Disk streaming is a data transfer approach in which data is read from storage devices in a continuous flow, emphasizing sequential access over random access. The goal is to deliver data to an application with minimal seeking and latency by using large, contiguous reads, buffering, and often asynchronous I/O and prefetching. Disk streaming can apply to various storage media, including hard disk drives and solid-state drives, though the performance characteristics differ between media types.

Key techniques include read-ahead caching, where the system anticipates future data requests and loads additional blocks in advance; buffering to smooth variability in I/O and processing rates; and asynchronous or overlapped I/O, which allows computation to proceed while more data is retrieved. Some implementations distinguish between direct I/O and buffered I/O, affecting how data bypasses or uses the operating system cache. Prefetch distance and buffer sizes are tuned to balance memory usage against throughput.

Typical use cases involve scenarios requiring high throughput of large, sequential datasets, such as local media playback, streaming of large files for analysis, and pipelines in data processing or scientific computing. Applications that load large assets gradually, such as game engines streaming assets or video editing workflows, also benefit from disk streaming techniques.

Limitations include poor performance for workloads with random or sporadic access patterns, potential startup latency to fill buffers, and the need for careful tuning of prefetching and buffering strategies. Hardware characteristics, such as seek times on HDDs and bandwidth on SSDs, strongly influence effectiveness. Related concepts include streaming I/O, prefetching, and memory-mapped or direct I/O.