HDD (Hard Disk Drive)

An HDD (Hard Disk Drive) stores data magnetically on rapidly spinning platters. A moving read/write head positions over tracks to access data, which makes it mechanical and slower than flash storage.

Why it matters

HDDs remain popular for bulk storage, backups and archives because the cost per terabyte is low. Typical speeds are 5400 or 7200 RPM, with faster enterprise models.

Because of the mechanical parts, HDDs are sensitive to shock and have much higher access times than an SSD, especially for many small random reads.

Example

7200 RPM = 120 revolutions per second
Average rotational delay is about 4.2 ms

That half-rotation wait plus head movement is why random access on an HDD takes milliseconds, while sequential reads of large files can still be fast.

Common mistakes

• Running an operating system or busy database on an HDD when speed matters.
• Moving or knocking a spinning drive, which can damage the heads.
• Ignoring SMART warnings about reallocated sectors.

Related

• SSD
• RAID
• SATA
• NAS

यह पेज सामान्य जानकारी है, जिसे हमारी संपादकीय टीम ने लिखा है और दस्तावेज़ीकरण बदलने पर अपडेट किया जाता है। सर्वर और प्रदाता अलग-अलग होते हैं, इसलिए बदलाव पहले सुरक्षित तरीके से जाँचें। देखें: संपादकीय नीति और अस्वीकरण.