Why Can't I burn 8.5GB to an 8.5GB DVD-R DL?

Hi -Q--

For the same reason as this:

Mac OS X and hard drive manufacturers report hard drive capacity differently (SSD Media excluded)

Luck-

-DP

You should be able to get about 7.7 - 7.9 GB or so on the "8.5 GB" disc. It has to do with the way the disc manufacturers define a gigabyte (the hard drive manufacturers do the same).

Your 8.5 GB disc has approximately 8,500,000,000 bytes available on it. The disc manufacturers define a gigabyte as 1,000,000,000 bytes (1,000 x 1,000 x 1,000), so that's how they arrive at 8.5 GB. Computer operating systems define a gigabyte as 1,073,741,824 bytes (1,024 x 1,024 x 1,024) so when you divide 8,500,000,000 bytes by 1,073,741,824, you get 7.916 GB. Other formatting information and whatnot reduces the usable space further.

Verbatim is probably the top brand for the double/dual layer discs.

I'm not sure what you're burning onto these discs, but if you are creating DVDs to play in a standalone DVD player, you should be aware of the serious limitations that DVD-R DL discs have and DVD+R DL discs don't.

Every file and folder takes up a chunk of data no matter how much is actually written. It is a throwback to old data file structures that only the must learned are allowed to see. Or something like that.

Anyway, it would be similar to allocating a one-gallon jug on an automatic milking machine for each cow even if the cow only produces a quart of milk. Gonna keep the cow. Need the milk. Machine won't accept one quart buckets.

A paradox.

Luck-

-DP