Higher capacity DVD-R's ...

[djarran]

It's actually sneakiness/manipulation on the part of the marketing/advertising bods for the disk manufacturers. Since a Kilobyte is actually 1024 bytes, a megabyte is 1024 kilobytes and a gigabyte is 1024 megabytes, a "4.7 gigabyte" DVD really holds something like 4,681,514,352 bytes - in advertising /marketing speak (since they're used to kilo=1000, mega=1,000,000 and giga=1,000,000,000) that's 4.68 Gb, or "nearly 4.7". Because 4.7 is a rounder number (the buying public really doesn't like decimals, according to advertising/marketing gurus), the DVDs are touted as being 4.7Gb, not 4.68Gb or the "real" size 4.36Gb (too many decimals, and too small - people won't pay for a 4.36 Gb DVD when the next manufacturer is selling 4.7Gb DVDs, will they?).

The same principal applies to hard disks too. Get the number in bytes and do the arithmetic. My 55.4 Gb iMac drive is about 59,485,279,000, that's "nearly 60Gb", so it was marketed as a 60Gb drive.

Dave

 

[Krevinek]

It's actually sneakiness/manipulation on the part of the marketing/advertising bods for the disk manufacturers. Since a Kilobyte is actually 1024 bytes... <snip>

Actually, it is honesty on the part of the disk manufacturers. Kilo is a standard prefix for 1000, Mega for 1 million, etc... Early on Kilobyte was used as 1024 because it was 'close enough' and was easier to manipulate on a computer with the slow processors. The software writers have been stubborn to change and use 1000 like the real prefix should be, or to adopt the proposed standard prefixes for powers of 2. Plus you have the storage losses incurred by the file allocation tables and other such data.

On the topic of high-capacity DVD burners, the problem lies in the fact that dual-layer DVDs can't be burned yet AFAIK.

 

[Urbansory]

Got my burner a little over a hour ago, good ole FedEX 2 days early, I installed it, burned a CD to see if it works, now I need to do some serious archiving. Good thing i went to the Apple Store yesterday to get my DVD-Rs.

 

[brianleahy]

A manufactured DVD contains a layer of aluminum trapped between two layers of transparent polycarbonate.

The aluminum layer is what gets stamped. A master "negative" plate is used to stamp all the pits into the aluminum layer in one mighty stroke, BEFORE polycarbonate layers are added. Hence, once the mastering process is complete, thousands of DVDs can be made VERY quickly and cheaply.

By contrast, burnable discs use various types of reflective dyes, rather than aluminum, inside the polycarbonate layers. The pits are burned in one-by-one with a laser.

Under no circumstances are the pits actually on the OUTSIDE of the disc, where you could touch them with your finger.

http://members.ozemail.com.au/~brierley/dvd/FAQ.html#5.1