- Post
- #241033
- Topic
- Disc Errors
- Link
- https://originaltrilogy.com/post/id/241033/action/topic#241033
- Time
Originally posted by: andy_k_250
What is the likely explanation here? Did I just happen to get a spindle of sketchy DVD's? Is my writer causing these errors?
If a disc can read properly on a PC, does that mean that there aren't any fatal flaws in my backup copy? I would hate to think some of the DVD's are now junk and that I would need to get reburns of certain things.
Thanks for any advice!
What is the likely explanation here? Did I just happen to get a spindle of sketchy DVD's? Is my writer causing these errors?
If a disc can read properly on a PC, does that mean that there aren't any fatal flaws in my backup copy? I would hate to think some of the DVD's are now junk and that I would need to get reburns of certain things.
Thanks for any advice!
Store-branded DVDs are crap quality, to start with. Even if you get a good burn, the crappiest discs can start deteriorating in as little as a year. So, yeah, you really should re-burn.
Because your problem is in the same spot every time, it sounds like there's a problem with "shift points".
Player software/hardware can skip over an unrecoverable bad spot, without showing a problem. But the disc will be fatally flawed.
Discs can have a zillion correctable errors and merely read slowly. Damage/decay can build up, then, without warning, bam, gone.
Disc errors are sneaky...
Different burners/readers might stand a better chance of reading. Your odds improve with newer firmware. There's a lot more to say, but I'll try to keep it readable, heh. CD Freaks is an invaluable resource. Read and search before posting questions, though...
Shift Points:
To get the faster burn/read rates (anything over 4x, if memory serves), the drive changes the spin speed, at various points.
At those "shift points", there will be a cluster of recoverable errors. If your drive's firmware works well with that kind of disc dye formulation, then there should be a relatively small number of errors. At the other extreme, there could be massive clusters of errors at any of those shift points. The tiniest bit of disc decay can send it over the edge.
Newer firmware versions have better strategies for burning & reading various dye formulations (whichever ones they chose to improve).
Better discs should help. But your drive's firmware might be picky about which ones. That's a long subject...
Testing:
First, test a few discs. If you have Nero, you can do a Transfer Rate Test.
In newer versions, it's:
StartSmart -> Extras -> Test Disc -> Benchmark
(In some versions, there's a "Transfer Rate Test" that doesn't waste time with a whole barrage of other little tests).
The smoother the curve, the better. In your case, expect to see a deep dip near the end.
It the test stops with a read error, then you got problems... (see the recovery section below).
If you don't have Nero, look at CDFreaks, about CDSpeed 2000.
If you can run a Disc Quality Test, you can see a graphical display of the errors, plus a quality score. Most drives can't do that, tho'.
Good Discs:
A great burner can make great burns on crap discs. But crap discs deteriorate quicker...
DVD Burnables use dyes, so they wont last as long as the pits-in-metal of the pressed retail DVDs. Burnable discs are only as good as their dye.
Better dye means a better chance of a good burn.
Crappy dye can start deteriorating in as little as a year.
It's expensive to experiment to find a good dye formulation.
Japanese disc makers spend the money. And they spend a lot of money on quality control.
Taiwanese disc makers follow a cheaper buisness model. Their discs will never be as good. They can range from pretty-good to catastrophic, depending on which manufacturer, which line, and other stuff. (The situation used to be just as bad with blank CDs, but now many Taiwanese manufacturers have developed good dye formulations for CDs - but not yet for DVDs).
Since there haven't been many rigorous studies, and since DVD burnables haven't been around that long, and dye forumlations can be upgraded over the years, you can't predict how any particular disc will last. The safest thing is to stick with Made in Japan - those should last several decades.
The spindles/boxes/singles should be marked "Made in Japan" or "Made in Taiwan". It's fairly random, but a lot of people know about this stuff, so M.I.J tend to dissapear.
You would expect Made in Japan to cost a lot more. And they used to. But, these days, most brands of discs are bought from both Japanese and Taiwanese manufacturers, then sold under the same name.
A big exception to the "Made in..." rule is Verbatim, because they own their own plants. There are varying opinons of their quality, and there seems to be variability of quality, but most people seem to prefer the Verbatim brand for Dual Layer discs (the last time that I looked into it).
There might be other exceptions. I think that Ritek has a contract with another company to use an excellent dye in one line, but don't quote me on that...
Some brand names have different lines. Some of those lines are recommended a lot.
I like Taiyo Yudens from rima.com. They and some other online shops have nice bulk prices for quality stuff. Or, if you find a sale on Fuji's or Sonys, and pick out the Made in Japan, then you should be getting Taiyo Yudens. Rated 8X, but can be burned faster.
Other people can give you their recommendations.
If your burner is picky, you may have to experiment with different manufacturers's, even different types, to find some that your burner loves. The brand may or may not give you a clue. You would need to use a utility to read the "MID", but that's a long subject.
Storage:
Discs live longer if they are stored in darkness, coolness, and low humidity.
Opaque disc cases, spindles in a closed box near the floor, running the A/C, that kind of stuff.
Recovery:
Different burners/readers might have more luck reading. The best would be a Lite-On Recorder - excellent reader, mediocre burner.
IsoBuster will make a monumental effort to recover the data.
If there are spots it can't recover, you will at least get files of the right size, but the bad spots will be garbage data.
If there's an active torrent, you can repair the files in a few minutes...
Safest practice for the most important discs:
Two copies, on two different kinds of good discs, stored separately.
Pars for all the files. (QuickPar makes extra files for recovering damaged files).
