Whats the difference between a Live CD and a live DVD?

**bokaroseani** · 10-20-2005, 09:02 PM

Hi, I downloaded Knoppix 4.0.2 ISO image and burnt a CD and am using it now. Can anyone tell me what the difference is between the contents of this Live CD that I am using and the Knoppix 4.0.2 Live DVD that is sold from the vendors? From what I read, it looks like both of them have all the similar sort of programs bundled with the GNU/Linux OS. The only difference I am guessing is that files are more compressed in the CD-ROM than on the DVD. Am I right? If so, I would imagine that running from a Knoppix Live DVD would be faster than running from a CD-ROM (since it would take less time in decompressing the files from the DVD for them to be run on RAM). Is that correct?

**UnderScore** · 10-20-2005, 09:20 PM

The only difference I am guessing is that files are more compressed in the CD-ROM than on the DVD. Am I right?

It is not more compressed but there are simply more files on the DVD as compared to the CD. The CD uncompressed is about 1.9 GB of files and the DVD uncompressed is about 9GB of files.

If so, I would imagine that running from a Knoppix Live DVD would be faster than running from a CD-ROM (since it would take less time in decompressing the files from the DVD for them to be run on RAM). Is that correct?

Probably not since the de/compression routine is the same for both CD & DVD. If you see a speed difference, it could be attibuted to CDR versus DVDR media or the speed of the drive itself.

**Harry Kuhman** · 10-20-2005, 09:25 PM

Originally Posted by bokaroseani

. Am I right? If so, I would imagine that running from a Knoppix Live DVD would be faster than running from a CD-ROM (since it would take less time in decompressing the files from the DVD for them to be run on RAM). Is that correct?

No, you're wrong in two way. Running from a compressed image would actually be faster than running from an uncompressed image. reading a optical disk is much slower than the computation speed of decompressing a file, so reading a little and decompressing it is actually faster than reading an uncompressed file from disc. But the DVD does have more software on it.

I sure wouldn't fool with a disc reseller though if you don't have your own burner; there is plenty to keep you busy on the CD and you can download anything else yourself. If you look around a little on the mirror sites you should be able to find a list of the "packages" on the CD and the DVD.