DVD-R says 4.7 GB but only getting 4.3...why?

[Tmat16]

Hi
Newbie question here. I see that all DVD-r(w) and RAMS say they gold 4.7 GB of data. But when I insert a disk it says its 4.3 GB only. Why? Is there something special I have to do? Some special program?

Thanks in advanced

[Truman]

It is rather a marketing trick. They make you believe, that 4.7 GB=4,700,000,000 Bytes, but it isn't.
4,700,000,000 Bytes / 1024 / 1024 / 1024 = 4.37 GB

[DVantrease]

Yep, they use the same marketing with harddrives. I just put in a 60GB harddrive, and Windows reports it as 55.8GB. Technically 1k=1024 bytes, so 1GB=1024x1024x1024, but harddrive manufacturers define 1k=1000 bytes, so 1GB=1000x1000x1000. That way, they can market a 55.8GB as a 60GB drive.

(sorry if my math is bad)

[Tmat16]

Thanks for the info!

[Greg12]

I wondered why my 20 gig hdd is only 18 gig usable.

[TRILIGHT]

This may or may not be useful to you but I recently wanted to automate calculating such things so I wrote a bitrate calculator. It's nothing too special. Just an Excel spreadsheet. It's been very helpful for me though. It has two calculation sections as follows:

Calculation 1: Given the recording time needed and the audio bitrate, it will return the Mbps capture rate that should be used.

Calculation 2: Given the Mbps capture rate used and the audio bitrate, it will return the amount of time available on the disc for recording.

Some of this may be old news for those of you who know all this already but for newbies, it could really help. You can download a copy here...

http://www.trilight.com/dvdbitratecalc.xls

Feel free to let me know if you do or do not like it or feel it's helpful. I've found it pretty accurate and it's saved me some time.