Quirkiness of the drive (2 questions)

Just reinstalled my computer windows xp + sp2, no heres the problem:

  • Before i installed sp2 i placed a blank into the benq drive, it registeres a blank and in the properties it highlights 4.38gig free, however after i install sp2 it registers a blank (i assume…via the autoplay) however the properties of the disks highlights it as a raw with 0 bytes free or written…Is this the work of SP2 patch or is it just me?
  • are dvd disk only capable of writing up to 4.38gig, cause my discs say they go up to 4.7gig however in alcohol they only register 4.38gig free…what’s wrong?

Thanks mates

THe second point first (?! Whacky old me!)

The size difference comes down to annoying marketing. To make drives, whether they be Hard drives or disc capacities, see bigger they quote Gigabytes as being 1,000,000 Megabytes.

In fact, since PCs are based off binary (POwer of 2) It’s actually 1,024 Meabytes. (which themselves aren’t 1000KB, they’re 1024KB).

This small extra 24MB means that while it coud be quoted as 4.7 it works out to actually be 4.3GB.

The first one…I’ve had this too. I think it’s since it doesn’t ahve any way of writing to it and there is essentially no structure to a blank disc so Windows probably just says what it sees; A disc it can’t touch that’s devoid of info.

It DOES still say “DVD+R” on the disc icon in My COmputer? If so then at least it’s detecting the correct format. If you installed InCD and used DVD-RW/+RW then, in my experience anyway, you can see total free becuase InCD allows Windows to drag and drop files into it, and provides a file strucutre ot read.

Note: I am a newbie so this may all be wrong!

I see, thanks wise regarding the first question ive asked …thks for reminding me of basic comp science (i dont do it though)…
regarding my second question, no in the disk property it states it as a CD-R, which is whacky…hmmm
regarding the first q again, i dont even get 4.3 more on the lines of 3.8gig…even in nero and alcohol…it seems the bar is set at 3.8gig
i think its a marketing gimmick thet the discs are undersized…this was never the case with CD-R’s…

I found that, when it was on the SATA serillel adaptor, it would sometimes come up in My Computer as CD Drive. YAY!

It still did it’s ‘thing’ though. I’ve not rearranged it, via the advice of darius, to a clean IDE. It comes up right but due to little gaming obsessed brother and work I’ve not been able ot test it (ie put in the InCD formatted DVD+RW and see if it still writes)

PS What’s the quality of any DVD+RW that you burn? I did one or two tests but they showed quite a large amount of C2 errors as well as a plethora of C1.

However, it ran fine enough in it, and the laptops RW drive. I’m new to the idea of Disc quality checking but I presume RW media will always have higher error margins than R media.

does anyone have the same problem, undersized discs?

There is a difference between kilobytes (KB) and thousands of bytes, megabytes (MB) and millions of bytes, and gigabytes (GB) and billions of bytes. All DVD and hard drive manufacturers say GB where they should say BB (billions of bytes).

1 KB = 1024 bytes
1 MB = 10241024 KB = 1,048,576 bytes
1 GB = 1024
1024 MB = 1,048,576 KB = 1,073,741,824 bytes

A 74-minute CD-R disc has 333,000 sectors, 2048 bytes each; it holds 333,0002048=681,984,000 bytes, or 333,0002=666,000 KB, or 333,000/512=650.39 MB of data.

An 80-minute CD-R disc has 360,000 sectors, 2048 bytes each; it holds 360,0002048=737,280,000 bytes, or 360,0002=720,000 KB, or 360,000/512=703.13 MB of data.

The most common 12 cm DVD-R disc has 2,298,496 sectors, 2048 bytes each; it holds 2,298,4962048=4,707,319,808 bytes, or 2,298,4962=4,596,992 KB, or 2,298,496/512=4489.25 MB, or 2,298,496/(512*1024)=4.38 GB of data.

The most common 12 cm DVD+R disc has 2,295,104 sectors, 2048 bytes each; it holds 2,295,1042048=4,700,372,992 bytes, or 2,295,1042=4,590,208 KB, or 2,295,104/512=4482.63 MB, or 2,295,104/(512*1024)=4.38 GB of data.

That’s all there is to it.

Indeed. If you think the DVD capacity from the manufacturer is a kind of cheat in some way, well, here’s something even worse: YOU HAVE BEEN CHEATED FOR YEARS ALREADY! Just look at your hard drive capacity. :smiley:


agent009’s summary explains why the size issue didn’t happen in the CD world. CD was originally developed for music of 74min or 80 min length, not data of 650MB and 700MB. BTW, why 74min? Not 70 or 75? I don’t know.

When they realized that you can make DATA CD, 74min and 80min discs happen to translate into 650MB (= 682 Million Byte) and 702MB (= 737 Million Byte) discs, respectively. Thus the marketing naturally chose the words “650MB” and “700 MB”, because a human being isn’t good at remembering numbers such as 682 or 737 or 702. :slight_smile:

Buying a 700MB disc then finding out you have 702MB free space (plus some overburning possibility) will never happen again in the computer world. :bigsmile:

Its down to the fact the chairman/director of Philips/Sony specified he wanted a format that would be big enough to hold his favourite opera (or was it a clasical symphony) on 1 disk. This happened to be just under 74 minutes long.

Philips originally wanted CDs to be 11.5 cm in size, Sony wanted 12 cm, as the 11.5 cm disk would only hold around 60 minutes of music, not big enough for the pices of music.