I am curious and is really no big deal. When burning, with My Dvd there are some resolution options. One can set the burn to be progressive and the highest possible resolution (in theory this should produce the biggest file?). One would think, then, that the supposed size of the resulting file, would be close to the size shown of the file before the burn. Instead the resulting files are consistently less than that shown. For instance, a file which has, say, 15mb left after the supposed burn (7.5gb less 15mb) will actually produce an iso file of about 320mb - sometimes less, sometimes more. I have searched these files but, evidently, missed this issue.

This discrepancy would then give the user the wrong idea as to what he could actually burn, ie. the red part of the shown meter has little to do with reality, along with the supposed size. Perhaps I am missing something here?

Thoughts?

Your math doesn't work… I think you have "mb" where you meant "gb".

In any case, I will try one but it will take a while.

What you are experiencing has been round since the very early days of drives.

Each disk (magnetic) or disc (optical) has sectors of a fixed size. If you look at any file on your hard drive, you will see two numbers - one os the actual file size and the other is 'space on disk'.

What happens is that files cannot overlap sectors in use, so if you have a file that even uses ONE byte of a sector, that sector is flagged 'unusable' for the next file but it will show as 'free space' (confusing I admit).

Also, on any optical disc there has to be room for other data apart from the files themselves - the Table of Contents, End of File markers all use up small amounts of space - but the loss is cumulative

nope mb (megabyte). this is the space left/free before the 4.7gb is hit.

I think I am not explaining myself. On the bottom of the My DVD screen there is a horizontal status bar and, under that what I think is a running description of the probable space used on the DVD ("used: ?? free: ??) To the left is the size of the dvd to be burned. If the "used" amount goes over 7.4gb the horizontal status bar goes red and the "free" goes to a minus amount. What I have been trying to say is that the 'used' amount has nothing to do with the resulting size nor does the horizontal status bar have much to do with the result, either on disk or in an iso file. I have a file, for instance, that shows that the probable size will be 4545mb. When this project is sent to an iso file the reality is that the size turns out to be something like 3740mb which is a rather large difference. My quibble is that if the user pays attention to this, and they need more space they just might already have it - if they ignore what the program tells them. I have another file, for instance, that runs 455mb past the 4.7gb limit yet the resulting iso file is less than 4.5gb.

This is not a big deal for me and I can work around it. My thought is that users should be made aware that these probable figures are not accurate at all. I only use this program to make slideshows when we take a trip as I can give them to the kids and they can see what insanities we have been indulging in. The only real problem I have had was just making the program run. I took care of that by doing a slash and burn on my computer (covered elsewhere). It turns out that the problem was not with Roxio but with my machine <sigh> I should also mention that Roxio seems to have only updated creator 10 one time. Nero, on the other hand, with their latest and greatest, only months old, has gone through over a dozen 'adjustments'. I also own that program and when I first got it it simply would not even run (7 iterations back). Their response was that I debug their program for them. I am giving them more time to get it right and have decided that I am not going to do free beta testing - been there, done that.........

I think what may be happening (and here it's just a guess) is that the program is allowing for overhead space in the reported file size and saying, yep, it's a 4.3 GB disc, but you are only going top be able to write X.X GB to it.

You also have to keep in mind that '4.7 GB' as stated by a drive maker is actually lower than you would think (drive and disc makers both use numbers to the base 10 where 1,000 bytes = 1 KB, where the OS actually uses numbers to the base 2 where 1,024 bytes = 1 KB). The result is that a disc's '4.7 GB' is actually quite a bit smaller than 4.7 GB as read by an app (I'll let you work out the math there )

I suppose it all depends what convention the program is using

Correct. The ISO does not include the Write In or Write Out portions because they are standard and the burn program will put them in on its' own. And they will be different depending on 'dash' or 'plus' media.

The estimate is based on the usable space and of course is an estimate. It cannot be precise until it actually renders the project but who wants to wait hours for a perfect answer when a good guess is available at the moment.

I suspect that I have beaten this dead horse enough. However, the suggested figures are simply waaay underestimated, based on my results which was my original whine. I suspect the estimate could be decreased by 10% with little problem. Just a thought........

Sorry but you would be wrong.

The ISO is not a complete file, there is more to it than what you see.

If you burn a Folder you will end up with another different number and you cannot draw any conclusions from that one either.

Roxio does know something about this. Even MS would not touch burning optical media! The burning you see in XP and Vista was written by Sonic/Roxio for MS.