A CD-ROM sector contains 2,352 bytes, divided into 98 24-byte frames. Unlike a music CD, a CD-ROM cannot rely on error concealment byinterpolation, and therefore requires a higher reliability of the retrieved data. In order to achieve improved error correction and detection, a CD-ROM has a third layer of Reed–Solomon error correction.[3] A Mode-1 CD-ROM, which has the full three layers of error correction data, contains a net 2,048 bytes of the available 2,352 per sector. In a Mode-2 CD-ROM, which is mostly used for video files, there are 2,336 user-available bytes per sector. The net byte rate of a Mode-1 CD-ROM, based on comparison to CDDA audio standards, is 44100 Hz × 16 bits/sample × 2 channels × 2,048 / 2,352 /8 = 153.6 kB/s = 150 KiB/s. The playing time is 74 minutes, or 4,440 seconds, so that the net capacity of a Mode-1 CD-ROM is 682 MB or, equivalently, 650 MiB.
A 1× speed CD drive reads 75 consecutive sectors per second.
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