Stress testing M-Disc BD-R vs regular quality BD-R

vbimport

#1

I thought that this was an interesting observation worth sharing: http://yss.la.coocan.jp/mdisc/mdisc_top.htm

Regular Panasonic HTL BD-R seems to hold better when boiled compared to Verbatim M-Disc BD-R.

However this may not be fully indicative of real world durability under non-boiling conditions. :smiley:


#2

That is really strange. It crossed my mind that they mistakenly switched graphs :slight_smile:


#3

Not Good! My Japanese is a little rusty, but might they have an axe to grind?

It did seem like the M-Disc might have been the one on the bottom (the entire time) thus would have taken the hottest of the heat, with the top disk floating above.

Still, it’s not a good result.


#4

Two things I have been saying for a long time:

-M-Disc BD-R don’t appear to be substantially different in composition or function to regular HTL BD-R discs.

-There is nothing special that would make them physically ‘robust’ so tests involving boiling, freezing, dropping etc appear largely pointless.


#5

Just throwing this out there, but unless I’m mistaking reading the results of M-discs in other topics, they, too display increasing errors with age. If so, this is disappointing because I was under the impression that HTL disks, with their inorganic data layers, were largely impervious to age. Y’know, data written to metallic or mineral layers is stable compared to that written to dye layers. :frowning:

So now I’m wondering whether to invest in HTL optical tech at all. Maybe better to archive to a dedicated hard drive that’s for storage only, at least until a truly permanent data storage medium comes along.


#6

Pointing out a small thing: some metal is highly reactive with oxygen, so if a disc has bad sealing, then oxygen can corrupt it.

And if M-Disc BD-R isn’t especially special, and uses similar metallic setups, then it’s susceptible to the same thing.

Plus all optical media written using a laser is susceptible to influences of light. That just comes with the territory. Same thing with heat and moisture, to varying degrees. Then there are scratches, issues with moisture, and the like, and protecting media is complicated.

Even with the discs properly sealed, the substrate is still porous, so air can get in and slowly work at it.

Compare to hard drives.

Hard drives are technically susceptible to losing their magnetic charge over time (unlikely) or having a physical fault preventing data access (more likely, for varying reasons, even if a drive sits unused). They’re not quite susceptible to light, but they are susceptible to physical shock, as well as electric shock. Then there’s the issue of moisture, and possible internal contamination over time (not likely, but possible). - The physical faults could come in with components seizing (motor fails to spin at correct speed or can’t spin at all, drive can’t move read-write heads, etc), or read-write heads get damaged, or other issues.

The downside to a hard drive is, I’m assuming you’ll be getting something fairly capacious. Even at 250GB or 500GB, that’s somewhere between 5 and 20 easily-obtained single or dual layer BD-R discs. If a drive fails, you lose that entire cluster of data. You also have to bring that hard drive online more often if you are intending to make incremental backups, which means it cannot just rest idly. This can be seen as raising the chances of failure, at least by a bit.

So I wouldn’t write either one off or bring one up as as being superior, unless you take into consideration how you’ll be backing things up, how often you’ll be accessing it, and how you’ll be storing things.

(I’m sure we’ve had a debate over the pros and cons of various storage media, but I’m currently too lazy to pull those conversations up. :p)

That said, which threads are you looking at which give you pause over optical media?


#7

[QUOTE=Albert;2771605]Pointing out a small thing: some metal is highly reactive with oxygen, so if a disc has bad sealing, then oxygen can corrupt it.

And if M-Disc BD-R isn’t especially special, and uses similar metallic setups, then it’s susceptible to the same thing.

Plus all optical media written using a laser is susceptible to influences of light. That just comes with the territory. Same thing with heat and moisture, to varying degrees. Then there are scratches, issues with moisture, and the like, and protecting media is complicated.

Even with the discs properly sealed, the substrate is still porous, so air can get in and slowly work at it.

Compare to hard drives.

Hard drives are technically susceptible to losing their magnetic charge over time (unlikely) or having a physical fault preventing data access (more likely, for varying reasons, even if a drive sits unused). They’re not quite susceptible to light, but they are susceptible to physical shock, as well as electric shock. Then there’s the issue of moisture, and possible internal contamination over time (not likely, but possible). - The physical faults could come in with components seizing (motor fails to spin at correct speed or can’t spin at all, drive can’t move read-write heads, etc), or read-write heads get damaged, or other issues.

The downside to a hard drive is, I’m assuming you’ll be getting something fairly capacious. Even at 250GB or 500GB, that’s somewhere between 5 and 20 easily-obtained single or dual layer BD-R discs. If a drive fails, you lose that entire cluster of data. You also have to bring that hard drive online more often if you are intending to make incremental backups, which means it cannot just rest idly. This can be seen as raising the chances of failure, at least by a bit.

So I wouldn’t write either one off or bring one up as as being superior, unless you take into consideration how you’ll be backing things up, how often you’ll be accessing it, and how you’ll be storing things.

(I’m sure we’ve had a debate over the pros and cons of various storage media, but I’m currently too lazy to pull those conversations up. :p)

That said, which threads are you looking at which give you pause over optical media?[/QUOTE]

Well, offhand, I’d use a backup HD on manual, not with any auto-backup software. Also, I’m past being a packrat. Just important files are to be archived. Stuff like documents, rare and old game installation files, that sort of thing. So even 1 TB would be far more than I’d need for the foreseeable future. And my PC is kept in a safe and environmentally moderate and stable location. So no probs there.

Since about 2000 I’ve been a fan of optical storage for archiving so there’s no bias against it. But this got me to doubting optical, in particular the updated screens from a period of a few years.

We’re used to seeing more degradation from dye based disks, of course, but the fact that it appears there’s some happening to these M-discs makes me wonder just how long will they really hold data? I was expecting M-discs, and HTL, to show virtually zero errors with time. Like 1000 years, the hype goes.

:confused:


#8

Such kinds of tests are irrelevant for me,because those are not normal circumstances…for example,a diamond can last millions of years,while iron can rust away in a MUCH shorter lifespan…:bigsmile:
But if you hit the diamond with a hammer,you can smash it to pieces,while the iron can take that hit easily…:iagree:
IMHO,no-1 can really predict the average lifespan of M-discs,or even regular ones ATM…


#9

Looking at that DVD+R M-Disc progression by czary2mary1, I wouldn’t say there’s any noticeable degradation. I see a clump of digital errors which appeared in 2015, which is still present in 2016, but that clump looks more like what might be caused by a scuff/scratch. I will very quickly say that degradation can start from one point anywhere on the disc, but the fact that from 2015 to 2016 there’s basically no change makes me think it was degradation.

We can also look at the BD-R http://club.myce.com/f179/millenniata-m-disc-bd-r-ritek-336254/index2.html#post2769056 (post #30). When looking at that scan, yes, you see more errors. However, there are also more samples taken (which, just for the sake of clarity, means to me that the drive managed to tell the software MORE information about this disc), which automatically means more errors are reported. Now, the spiky bits appear on a lot of BD scans, and I have no explanation.

When I think of degradation, I think of a noticeable rise in digital errors for a large portion of the disc. The base PIE/PIF levels (for DVD) or LDC/BIS levels (for BD) are higher, and it may be over a chunk of the disc, or it may appear as a mountain of new errors, or greater spikes of PIF/BIS. On the discs under discussion, I do not see a worrisome increase in the amount of errors at all. Rather looks like normal variance and acceptable glitches.

I look at things in a similar manner to roadworker, too. :slight_smile: Which reminds me: 1000 years is super unbelievable to me. It could last that long, but as we say, we can’t make predictions!


#10

With hard disks there are more parameters that you have to worry about. Albert mentioned them. And many of them can render your data inaccessible instantly. When a hard disk fails it fails without notice (most of the time).
But when an optical disc fails, it fails during the course of many years (maybe not even in our lifetime if quality media is used). This gives you some peace of mind because you can scan your discs occasionally and determine their state.
My DVDs from many years ago are still good, here’s one in the attachment.
I can’t be 100% sure but I think somewhat higher PIE was there in the beginning too. This is not a big deal, I had new burns with PIE around 1600.

So, my point is that optical media can be very reliable. And in my case, much more reliable than hard disks since I had 3 HDD failures and not a single DVD failure in 11 years (out of around 300 probably).
Now I switched to blu ray backup and I’m not even thinking about using hard disks as archival devices. The risks are too great.