Not only would cache
be more efficient
(best bang for the buck), but a CD that can hold 650, 700 or 800MB of information actually holds much more in the form of error correction
- which is why you'll see ISO
s that are apparently larger than the data they hold.
You would need to copy this error info to the memory as well since many copy protection scheme
s rely on it.
A GB of memory
isn't too expensive
now, but most cd-rom access is less than a few MB, so it would actually be less effective to spend the 2 minutes or so to copy the entire CD to the memory. It would be better, since HD space is /so/ much cheaper to use a virtual CD program that puts the image on the HD, and simulates one or more CD-ROM drive
s. Then you are relieved of even the burden of putting the CD into the drive when you want to play.