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The original was posted on /r/datahoarder by /u/danielrosehill on 2024-01-23 22:51:34+00:00.

Hello datahoarders!

Sorry for posting a couple of times on the sub today. I’m finishing off a few years of data archival and some questions and thoughts have come to mind in quick succession.

So, I’m one of the oddbods using the M-Disc for archiving personal data (videos, podcasts, documents). It’s working out nicely for me.

I know that there are some on the sub who are very sceptical of the M-Disc. To be frank, I’m not one of those and believe that Verbatim is producing legitimate M-Discs after buying the technology from Millenniata (with Ritek, AFAIK, as the only other licensee). I think it’s an intriguing technology that tried to creatively tackle an important topic - data permanence - that the storage industry has largely, and continues to, ignore.

The patent about the composition of the disc layer is freely available on Google Patents for anyone who wishes to read it. This PDF also offers a little bit of insight into what’s so special about the all-important inorganic layer that holds the data (as compared to the organic dyes that are now otherwise ubiquitous).

A common bone of contention against the M-Disc goes something like “well, if a regular Blu Ray can write the discs, it can’t be that special.”

I’ve looked into the compatibility question a little and Millenniata did indeed state from the outset that most Blu Ray burners would be compatible (with advances in Blu Ray writing technology since, it seems that pretty much everything works with it). The picture with the DVD M-Discs is/was a little more complicated but is quickly fading into irrelevance (Verbatim never produced them to the best of my knowledge; there’s just old Millenniata stock on the market and some stuff with Ritek; I have no idea if the latter is new or old).

In any event…

I interviewed the guy who invented the technology on YouTube a couple of years (he’s a storage scientist over at Bringham Young). I dropped him an email today to ask for his thoughts on appropriate ways to test the longevity of the disc (his answer: accelerated ageing testing is imperfect but probably the best methodology).

He also wrote a couple of lines about the compatibility between the discs and burners. With his permission, I’m reproducing these lines from our email exchange:

About the writing of Mdiscs – we worked LONG and HARD to make it possible to write Mdiscs in ordinary drives (takes a different amount of laser power and a different write strategy), and were mostly successful with the DVDs (only needed a relatively small increase in laser power – about 20% more – and the laser in the drive was already capable of this; and did need a different write strategy to reduce the jitter, but that write strategy was already available in most ODDs; we just had to specify it). We were completely successful with the BD Mdisc – it was able to be burned in any BD-capable ODD because it used one of the standard write strategies and standard laser power. We considered that a coup-de-gras.

In any event, I thought that tidbit might be of interest to the M-Disc archivers here - whether you’re a skeptic or, like me, a believer.

TL;DR

The guy who invented the M-Disc says that they succeeded in getting the M-Disc to work with pretty much all Blu Ray hardware. Apparently the DVD product did end up requiring some additional strength from the hardware but the Blu Ray didn’t. He says that he and his co-inventors considered that a big achievement.