Learn about the technologies behind the Internet with The TCP/IP Guide!|
NOTE: Using robot software to mass-download the site degrades the server and is prohibited. See here for more.
Find The PC Guide helpful? Please consider a donation to The PC Guide Tip Jar. Visa/MC/Paypal accepted.
|View over 750 of my fine art photos any time for free at DesktopScenes.com!|
Internal Buffers or Cache
Virtually all CD-ROM drives today have on-board memory buffers that are used to improve performance. These are also sometimes called cache memory, although using this term is problematic because caching also refers to using a system memory cache to reduce accesses to the CD-ROM drive.
The internal buffer is used to improve performance by holding information that is read from the disk so that it is available to the system when needed in the near future. This improves performance by reducing the number of physical accesses that are required to be done to the actual disk surface itself, just the way the built-in cache on a hard disk controller logic board works.
The larger the buffer, the more performance will be augmented--to a point. There is a matter of diminishing returns as buffers get larger, and you may not see a huge difference in speed in a drive with 1 MB of internal buffer compared to one with 512 KB. Of course, extra buffering certainly doesn't hurt.
Next: System CD-ROM Caching