Tested: How Many Times Can a DVD±RW Be Rewritten? Methodology and Results
167 points
3 days ago
| 10 comments
| goughlui.com
| HN
parsimo2010
8 hours ago
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I love this and I love seeing that it's from 2026 and someone still took the time to do all this testing- it must have been seriously involved because even at 6x it takes a while to fill up a DVD, and then to repeat that hundreds of times on several discs would be an eternity.

I haven't used a DVD+-RW in several years, as wireless file transfer over networks and flash drives handle pretty much all of my needs now, but I sure used the heck out of my DVD writer when I had it. I had no idea these discs could go hundreds of writes before failure, I always got paranoid about reliability and probably never went above 20 writes on a disc.

Edit: at the end of the post the author says, "that’s about 4020 hours across two drives, 5248 burns and both drives are still seemingly operating just fine." What a colossal amount of time.

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avadodin
1 hour ago
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I thought two-three times. Maybe a dozen. I always treated all kinds of writeable CD/DVDs as if they were one-write and done.

To be honest, it hurts every time I write to an SSD drive — which is all of the time these days.

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CamelCaseCondo
2 hours ago
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From my personal experience, the article and the comments I read here they seriously undersold the reliability of rewriting. For any other RW medium (audio or video cassettes, even floppies) I remember ad campaigns by Sony, TDK, Philips, … on tv. But not for these.
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rkagerer
1 hour ago
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I feel in general the industry was more conservative making these kind of estimates than it is today. I assume they also benefited from years of CD-RW field experience honing the tech.
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rlv-dan
4 hours ago
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I wrote an article in a similar vein some years ago that might interest you too:

https://www.rlvision.com/blog/how-long-do-writable-cddvd-las...

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krige
3 hours ago
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Ye, having experienced the "joys" of rewriteable CDs, I completely skipped the DVD RWs, expecting more of the same. Guess it wasn't, but then again, thumb drives became a thing.
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htor
10 minutes ago
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I think what we are all really questioning about is: how many times can it be rewritten in Rust?
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tombert
7 hours ago
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DVD-RWs always seemed like complete magic to me. I had no idea how they worked, or why they worked. I made and wiped DVD-RWs as a teenager dozens of times, because my dad got annoyed that I kept using up all his DVD-R's, so I bought like three DVD-RWs and used them for all my experiments.

I don't think I got anywhere near the limits for any of them, as I don't remember getting any faults from them, but they were always cool to me.

I was also one of the happy few who had a DVD-RAM drive for my desktop as a teenager; I never really understood why DVD-RAM never caught on, because it seemed to work fine for me, and it was kind of nice not having to wipe the disk to erase stuff.

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Tuna-Fish
1 hour ago
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dvd-ram drives and media were always premium products, with the drives at least ~4x more expensive than the -r drives of the time, and the media was much worse than that.

When -r disks bought in bulk cost ~20c each, $10 disks are a hard sell.

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Dylan16807
2 hours ago
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I guess the drives just cost too much and so zip won until flash drives took over.
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ChrisGreenHeur
4 hours ago
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Well. There is a laser, the first time you write a DVD-RW the laser burns holes into the disc, those are your ones and zeroes. Then if you want to rewrite it you have to fill in the holes so the drive uses an epoxy covered brush to make sure the disc has a smooth layer, then it makes new holes.

It's really the one physically possible way to implement it if you think about it.

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blue_pants
3 hours ago
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Epoxy and brushes?

Doesn't it use a special metal layer, and the laser high-heats the spots to make them amorphous (to write) and then low-heats them to crystallize (to erase)?

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yibers
1 hour ago
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The DVD+RW actually used pencil and eraser technology instead. It was a surprisingly robust method.
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scientism
1 minute ago
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Then came DVD±RW which used the magic pen technology. Each time you write, it changed both the color of the disc and the data. Surprisingly enough if you did it long enough it ended in color/data corruption...
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s_dev
2 hours ago
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This is a troll.
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bityard
2 hours ago
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No, it's a joke
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awesomeMilou
4 hours ago
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Won't the epoxy run out at some point?
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ChrisGreenHeur
3 hours ago
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That's the amazing part, when making the holes the epoxy melts and drips down into the collection bucket that the brush uses
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afandian
10 minutes ago
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The original solution involved a very thick disc which could then leveled and re-pitted. The problem was that the change in mass over time made it hard to calibrate the acceleration.

It also put a high radial load on the spindle whilst mounted sideways which led to run-out.

And flooding the area with radon (a heavy gas) helped the disc to float a bit, but had unexpected consequences...

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thombat
2 hours ago
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It comes years too late, but I finally understand the reliability problems I had with a DVD drive mounted on its side. If only I'd had your insight then, I could have taken the PC to a playground and burnt disks on the carousel.
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jagged-chisel
33 minutes ago
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I wouldn’t have expected gravity to be a problem at these scales. Wouldn’t surface tension override here? Maybe I’m totally off base …
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mgrandl
3 hours ago
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I guess the holes are so microscopic, even one cubic centimeter would last for the lifetime of the device.
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15155
3 hours ago
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Or, you know, how the technology actually works: two different lasers and crystallization states.
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ChrisGreenHeur
57 minutes ago
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Sure, dvds work by magic crystals.
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sethammons
23 minutes ago
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Next you're gonna tell me that applications run on text you can write by hand. Pffft. Ain't no way
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doublerabbit
4 minutes ago
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LLM's are actually little elves from the DMT dimension. They got captured and compressed in to silicon cells that now been enslaved by the evil Pandora.

If you ask a LLM they will tell you it's true.

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grepfru_it
7 hours ago
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>Windows Updates

If you want to stop windows updates, make your internet connection a metered connection. Updates will only be allowed on-demand.

The more you know!

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dataflow
2 hours ago
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I'm pretty sure I read that at some point they started still allowing updates on metered connections, just slower or more critical or something.
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ocdtrekkie
6 hours ago
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If you have a Pro edition license most things Windows does are a registry key away. The entire policy branch of the registry is designed to have configuration pushed down from the network like when and how to update, but you can also set all of those keys manually.

(Also, no hacking is necessary to set up a Windows Pro install with a local account, just tell it you're going to domain join it.)

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tom_
6 hours ago
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The local account tip is a good one. I used it when setting up Windows 11 Pro on my desktop PC.

Regarding updates: you might not even need to think about registry keys! I found these Windows 10 group policy settings to work well for many years: https://news.ycombinator.com/item?id=18157968 - and I'm still using them with Windows 11, near enough, though it seems you now need to go to "Windows Update\Manage end user experience" to find the Configure Automatic Updates setting I mention.

(I've also switched to using option 2 (Notify for download and auto install) rather than 3 (Auto download and notify for install), on the basis that it sounds safer, and I've had no problems from doing that. Not to say that I actually remember having any problems from letting Windows download the updates ahead of time! - but I'm comfortable living dangerously.)

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avidiax
6 hours ago
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One hint for the wary: Don't delay feature updates for the maximum allowed in the group policy editor. I couldn't figure out why I was getting forced reboots for updates despite other policies requiring it to ask permission. Turns out that if the update hits the group policy maximum, it forces an update immediately, other policies be damned.

So set it to the max - 14 days if you want some time to apply updates at your leisure, and you are wary of non-critical updates.

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rkagerer
46 minutes ago
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If you don't want feature updates, go Windows 11 IoT Enterprise LTSC. It's a comparative breath of fresh air and what Windows should have been all along. No ads, no new unwanted bloat shoved down your throat, no mandatory TPM, and pretty much the longest security patch commitment of anything out of Microsoft. It works great as a daily driver.
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VorpalWay
3 hours ago
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You could also use an OS that doesn't tend to have dodgy updates that brick your system, such as most Linux distro. Nor force you to update if you don't want to.

Funny how a large company like Microsoft can't figure out QA, but volunteer Linux distros with much less resources can.

(A lot of Windows specific software works in wine these days, Valve's investment into improving it for games have helped for applications too. Not everything, and if you are stuck with such software, yeah that sucks.)

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zozbot234
4 hours ago
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DVD±RW is old stuff, I want proper phase-change persistent memory. Bring back Intel Optane and hook it up to a modern, high-performance PCIe bus.
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userbinator
4 hours ago
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The same site has an article on that: https://goughlui.com/2024/07/28/tech-flashback-intel-optane-...

Retention issues are a bit worrying.

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rkagerer
49 minutes ago
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This is awesome, thanks.

My understanding is Optane is still unbeaten today when it comes to latency. Has anyone examined its use as a workstation OS volume compared to leading SSD's?

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haunter
2 hours ago
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I wish there were dual layer RW discs. Afaik some were made but they never hit the consumer market in the end
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bsder
8 hours ago
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IIRC, the issue was never how often the DVD-R/W could be rewritten.

The issue was the fact that everybody assumed that the DVD-R/W discs had roughly the same lifetime as actual DVDs and that turned out to be woefully incorrect.

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hrmtst93837
2 minutes ago
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The quality differences between DVD-RW brands and batches were huge, with some discs barely surviving ten rewrites while others managed many more. Exposure to heat or sunlight kills them quickly, even though they were not marketed as disposable. For real archival needs, options like M-DISC, tape, or cheap SSDs are more reliable than rewritable DVDs.
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tjoff
3 hours ago
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People did? I thought that was common knowledge, as it also was for CDs. Not only that, compatibility with players were much worse.

Though there were times were RW discs cost as much as normal ones, and some friends of mine defaulted to buying RW even for stuff that was write once. I didn't get that, but for them the ability to, maybe, reuse the disc outweighed any reliability issues.

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karlgkk
5 hours ago
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I didn’t know there was a rewritable dvd format. My dad had a bunch of dvds, I used to love sneaking one off to play on my computer when I was a kid, since he stopped noticing when he got into bluray
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giuliomagnifico
4 hours ago
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Yes, they were present and not much expensive than standard ones. However, the issue was that they encountered problems/data loss after few rewrites.
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anal_reactor
2 hours ago
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Really astounding dedication! And to be honest, I'm really surprised that DC Erase actually revived discs. Maybe the next step is to pick one disc, and keep using DC Erase, and see when it absolutely and totally fails?

When I was a kid I read that you can format DVD-RW in a way that makes Windows see it as a normal filesystem. The next step was "can you install a video game onto a disc?" and the answer was "nope, you cannot, at least not Lego Star Wars".

Also, there was a strange phenomenon that I'd love to see someone explain. I burned The Sims 2 onto CDs. The game worked. After some time the disc would fail at a file called voice1.package. I burned a second disc, which would again last some time, and then fail at the same exact file. I went through many discs, each one displaying the same behavior.

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baCist
5 hours ago
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Very timely article! :)
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