Sequential write is the rate at which a storage device, such as a solid state drive (SSD) or hard drive, can record data written continuously to adjacent locations on the disc or memory. It is measured in megabytes per second (MB/s) or gigabytes per second (GB/s), and represents the fastest writing speed the device can achieve under ideal conditions.
Unlike random write performance, which measures how quickly a drive handles scattered, fragmented write operations, sequential write reflects what happens when you move or copy a large file in one go. Real-world tasks that benefit from high sequential write speeds include video editing, backing up large files, or exporting photo libraries.
You'll find sequential write speeds listed in product specifications and reviews. SSDs typically deliver 200 MB/s to over 7,000 MB/s depending on type and interface (SATA versus NVMe). Traditional hard drives are much slower, usually ranging from 100 to 200 MB/s. NVMe SSDs, the current standard for high-performance storage, consistently lead in this metric.
When buying a storage device, check the sequential write speed if you regularly handle large files or work with video, photography, or data backups. For everyday use like browsing and document editing, the difference becomes less noticeable. Pairing a fast sequential write speed with adequate storage capacity and a suitable interface ensures your device won't become a bottleneck when you move or create files at speed.