Re-write (RW) limits and compatibility compared to write-once (R)

Compared to solid-state flash memory which can be rewritten a finite amount of about 100,000 times and hard drives which can be rewritten a near-infinite number of times, optical discs with compressed audio on them are either non-rewritable (CD-R/DVD-R), or can only be rewritten about 1000 times, which includes having to erase the entire volume before re-writing (CD-RW/DVD-RW). In some cases 1000 write/erase cycles (including entire volume erasure per re-write) on RW optical discs vs. 100,000+ write/erase cycles on flash memory (while retaining old data) can be somewhat of a moot point with applications that have less demand for usage.

Another issue re-writable optical discs suffer from, is that the re-writable discs have less compatibility with older disc players, though most CD and DVD players that support MP3s and other compressed audio will support RW discs easily.

Longevity of service life

The dependency of moving parts for the associated equipment guarantees less runtime than solid-state portable media players for battery life reasons, as well as the overall service life. When being looped, an optical disc player can fail in less than one month when spinning uninterrupted, and solid-state portable media players can run for as long as 6 months uninterrupted without failure.

Shelf space

Yellow Book optical disc ROMs with compressed audio may free up as many as five Red Book audio CDs, but they still demand much shelf space, compared to external hard drives and solid-state flash memory.

Material degradation

Unlike mechanical disks with permanent housing such as hard drives, and solid-state devices like flash memory which generally has inexpensive but tough housing, optical discs typically have a reflective surface that can get damaged at relatively low thresholds of surface damage, in which if damage is just accidental, it could mean rendering it unusable. Also, the repeated handling of discs between jewel case and disc drive exposes the disc to dust, and also makes the disc liable to be damaged permanently.

Also note that some CD and DVD discs also have defective aluminum layers that can flake, and damage the disc naturally.

If an archival-grade disc is used, such as gold CD or M-DISC, the disc can last far longer than hard drives or flash memory.

File/volume size limits and access to files

Repeated insertion and removal of optical discs can occur when somebody has to deal with multi-gigabyte collections which can span across as many as 10 CD-Rs (or 5 DVD-Rs) or even more when lots more gigabytes were to be used. Sometimes when somebody is looking for a specific MP3 or similar; it can result in insertion and removal if more discs were used to increase the size of a library of files, in which copying the files to a hard drive, and archiving them there can be a workaround to ensure faster access to files.

Recordable Blu-ray Discs can somewhat solve this problem, but they too suffer from most other disadvantages. The high cost of stand-alone Blu-ray burners, as well as the higher cost of equipment with BD-ROM drives can negate buying sold-state flash memory instead, of which the re-writability of flash memory also negates Blu-ray's apparent advantages.