Optimizing CD-ROM File System Performance

The CD-ROM cache is separate from the cache used for disk file and network access because the performance characteristics of the CD-ROM are different. This cache can be paged to disk (the file and network cache cannot), which reduces the working set for Windows 95 but still allows for better CD-ROM performance. When Windows 95 is retrieving data from a compact disc, it is still faster to read a record from the cache even if it's been paged to disk because the disk-access time is much faster than the compact-disc access time.

Tip

A small CD-ROM cache makes a big difference in streaming performance, but a much larger cache does not pay off as significantly, unless the cache is large enough to contain entire multimedia streams.

To set the supplemental cache size for CDFS

  1. In the System option in Control Panel, click the Performance tab, and then click the File System button.
  2. In the CD-ROM Optimization area, drag the slider to set the supplemental cache size.

  3. In the Optimize Access Pattern For list, select a setting based on the size of your computer's RAM and CD-ROM access speed. The following list shows recommended settings related to RAM size and the size of the cache that's created.

RAM size

Optimize setting

Cache size

8 MB or less

Single-speed drives

64K

8 MB to 12 MB

Double-speed drives

626K

12 MB or more

Quad speed or higher

1238K


  1. Click OK, and then shut down and restart the computer.

For information about how VCACHE and the supplemental CD-ROM cache work, see Chapter 20, "Disks and File Systems."