Long-term reliability of dual/double layer media



I was just wondering if there’s any known facts about the reliability of single-layer vs. dual/double-layer DVD’s?

Let’s just assume that top quality media is being used… I want to know if it’s just as safe to burn critical data onto a dual layer DVD as opposed to a single layer. I’ve been using single layer for years, and the reliability is rock solid… But for some things it would be much more convenient to store things on a disc with more capacity.

I’ve recently purchased a large batch of what I think to be high quality DVD+R DL discs, but so far I’ve only used them for movies — nothing irreplaceable. I’m thinking more like 5-10 years down the road. So far, single layer DVD has never failed me. I have some data CD-R’s that are 10 years old and still work great, but something about multiple layers spooks me.

The fact that there are layers “stacked” on top of each makes me feel like something is more likely to go wrong. Is there any truth to this?

Any thoughts/opinions are welcome!


Maybe a bit. There is a thin 55-micron layer between two recording surfaces, but other than that, double-layer discs are structurally identical to single-layer: two 0.6 mm slabs of polycarbonate bonded together. If you don’t expose recorded discs to a lot of light or humidity, disc longevity will be determined, to a large degree, by the quality of dye and the quality of bonding, and either one has little to do with the number of recording layers.

Oh, and… if you plan to trust ‘something irreplaceable’ to optical media, burn three copies on three different disc types, in three different drives, and store the discs in three geographically separate locations :slight_smile: