new 3.7 iso size 715MB ? need a 700Mb CD or a 800MB CD

[Doublezz]

I wanted to download the new Knoppix 3.7 EN iso and the ftp site said that the iso size is
715,764 KB large. After downloading the iso the ftp dialog window showed a downloaded
file size of 698MB, but the file system again displays a 715,764KB file. Now I am confused.

Does this mean that a 700MB CD-R is too small and I will need an oversized 800MB CD-R?
Or are these just file system anomilies, and the iso will burn just fine on a 700MB CD-R?

Thank you for your insight...

Doublezz

[brunomfpaula]

i burn it last night and i stranged a little too, but you need only a 700 MB CD, maybe the file contains more information that is only used by the prog. you use to burn.
No need to worry !!!

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Bruno Marques
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[Markus]

715764/1024=698.98828125 which means that you have 1024 bytes in a kilobyte, 1024 kilobytes in a megabyte and so on...

EDIT: Found a link: http://en.wikipedia.org/wiki/Binary_prefix

[Doublezz]

Thank you for your helpful links, I think I now understand the problem.

To summarize, the problem is that there are two international systems of abbreviations, the (SI) Systeme Internationale decimal system using powers of 10, and the (IEC) International Electrotechnical Commission binary-units system using powers of 2. Using the abbreviations of one system to represent values in the other system is the source of our confusion, (e.g. 1KB = 10^3 or 1,000 bytes , NOT 2^10 or 1,024 bytes according to SI since KB is actually a decimal abbreviation).

To alleviate potential confusion with binary units, IEC created a binary-multiple abbreviation system. (e.g. 1KiB = 1024 bytes NOT 1,000). While this solution would effectively work if everyone used IEC abbreviations when referring to binary-units, this is unfortunately not the case in the real world. Most manufacturers still use the SI decimal abbreviations when referring to binary-units, hence a 700MB CD-R is really mislabled! Since a 700MB CD-R refers to binary-units of bytes 700MB should really be labeled 700MiB meaning 700 x 2^20 or 700 x 1,048,576 bytes = 734,003,200 bytes of capacity.

If manufacturers want to use SI abbreviations then they should rather 1) mark a 700MB CD-R as 734MB to be more accurate for consumers who count in decimal, or 2) relabel the CD-R to 700MiB. Undoubtably this would generate too many questions from customers who would want to know what a MiB unit is and there probably would be few salepersons who could answer correctly!

Anyway, now I see that ftp dialog download incorrectly labeled the file download size as 698MB, it should have said 698MiB or 732,942,336 bytes and my file system which read 715.764KB (i.e. 732,942,336 / 1024) should have said 715.764KiB. Finally, the CD-R manufacturer should have labeled the CD as 700Mib or 732MB. But then this would mean that all the operating system software that was written prior to 1998 when the IEC system was created would have to be 'fixed' with IEC abbreviations. It would also mean re-educating all of us old-timers who do not know any better ... a task that is probably impossible!

UuurggGHH!!!!

Doublezz

Bottom line... a 700MB CD will work fine on Knoppix 3.7!

[firebyrd10]

Yet another reason a 200 GB hardrive does not contain 200 GB

[Shadda]

i burn it last night and i stranged a little too, but you need only a 700 MB CD, maybe the file contains more information that is only used by the prog. you use to burn.
No need to worry !!!

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Bruno Marques
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It's called overburn. You'd be hardpressed to find a brand of cd that uses exactly 700mb. Some of my K-Hypermedias can pull 800mb overburn. It's neat to figure out the overburn capabilities of your CD-Rs, but it IS a trial/error proccess :)