Then there’s the question of which applications actually benefit from a faster CD-ROM drive. Most multimedia titles are optimised for double or, at best, quad-speed drives. If video is recorded to play back in real time at a 300 KBps sustained transfer rate, anything faster than double-speed is unnecessary. In some cases, a faster drive may be able to read off the information quickly into a buffer cache, from where it is subsequently played, freeing up the drive for further work. This is rare, however.
Pulling off large images from a PhotoCD would be a perfect application for a faster CD-ROM drive, but decompressing these images as they’re read off the disc results in a performance ceiling of quad-speed. In fact, just about the only application which truly needs a fast data transfer rate is copying sequential data onto a hard disc; in other words, installing software.
Fast CD-ROM drives are only fast for sustained data transfer, not random access. An ideal application for high sustained data transfer is high-quality digital video, recorded at a suitably high rate.MPEG-2 video, as implemented on Digital Versatile Discs (DVDs), requires a sustained data transfer of around 580 KBps, compared to MPEG-1’s 170 KBps found on existing White Book VideoCDs. However, a standard 650MB CD-ROM disc would last less than 20 minutes at those high rates, so high-quality video will only be practical on DVD discs, which have a much higher capacity.
- CD-ROM Red Book
- CD-ROM Yellow Book
- CD-ROM XA
- CD-ROM Green Book
- CD-ROM Orange Book
- CD-ROM White Book
- CD-ROM Blue Book
- CD-ROM Purple Book
- CD-ROM CD-I Bridge
- CD-ROM Photo CD
- CD-ROM File Systems
- CD-ROM Manufacturing
- CD-ROM The Disc
- CD-ROM Operations
- CD-ROM Digital Audio
- CD-ROM CLV
- CD-ROM CAV
- CD-ROM Applications
- CD-ROM Interfaces
- CD-ROM DMA vs. PIO Mode
- CD-ROM TrueX Technology