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View Full Version : [ubuntu] Why are my 8.5gb DVD+R DL showing up as 7.9gb?



blazini
March 29th, 2009, 07:10 PM
I've tried 3 different burning apps now and they all report 7.9gbs. I don't remember this happening in XP. I'm using Verbatims and it's really irking me cuz I want to get 8.1 gigs on this disk but can't

jo4hnc
March 29th, 2009, 07:33 PM
Maybe this will help.

"Q: DVD: I tried to record a 4.5GB file onto a 4.7GB DVD but it wouldn't fit. How come?

A: The problem is that computers/DVD drives and blank media count differently. The computer counts according using base ten in its binary system.

The DVD camp decided to count bytes in a decimal system. Therefore, a 4.7GB DVD can only hold 4.49GB of content, using computer terms. Also keep in mind that a small amount of capacity is used up for formatting.

* 1GB = 1 gigabyte = 1,073,741,824 bytes = 230 in computer terms
* 1GB = 1 gigabyte = 1,000,000,000 bytes in DVD terms"

miegiel
March 29th, 2009, 07:36 PM
8.5*1000^3/1024^3=7.9

It could be the same as with harddisks. Where sometimes 1GB = 1000000 bytes (1000^3) and sometimes 1GB = 1073741824 bytes (1024^3).

jo4hnc
March 29th, 2009, 07:44 PM
Exactly. It's why your 300gb hard drive shows 279gb capacity.

blazini
March 30th, 2009, 02:49 PM
Exactly. It's why your 300gb hard drive shows 279gb capacity.

Oh, see now I feel stupid. I know how hard drive space is counted differently, but it never dawned on me that DVDs were subject to the same backward *** system. I rarely burn DLs, and you don't notice quite as much with single layer disks since the difference is about half. Though it does explain why I can only get 4.3gb on a "4.5gb" disk.