Tested: How Many Times Can a DVD±RW Be Rewritten? Methodology and Results | Hacker News Reader

Tested: How Many Times Can a DVD±RW Be Rewritten? Methodology and Results

goughlui.com

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.

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.

For archiving, DVD is 4 GB and who knows how long the medium will last.

LTO-6 drives go for 300-500 EUR refurbished. You need a FC switch or HBA. Each tape holds 2+ TB uncompressed data.

As for NVMe, if you do a lot of writes (e.g. DB's, Docker), go for enterprise. If you do that, grab one with PLP. You'd use it also as a cache for ZFS.

Fibre channel HBAs really cost peanuts. Because there's tons on the second hand market and the only ones who want them are enterprises who don't buy second hand shit without a support contract (they usually dump them when the support is up, that's why there's so many working ones on the market)

So I get €300 cards for €20, it's a joke. Really great though because they're really amazing for tying storage together and they can do point to point just fine. No switch needed.

The one drawback is the convoluted software chain around it, I used to work with SANs but if you don't it might require a little investigation :) The client side is pretty easy, the target side is harder (this is the part that is normally covered by a SAN).

But the biggest problem with LTO drives and home use for me is the terrible noise they make. If 3D printers sound like robots having sex, this is more like robots getting tortured.

I made a mistake in my post. I meant to say FC HBA or SAS HBA. I went with a SAS one which I use with a HBA, but the FC ones were cheaper (both FC LTO drives as well as FC HBAs) but would've still required a FC switch). I already got some fiber through my house though, so it'd have worked well. But I went with SAS which was considerably more expensive. 40 dB ain't fun, indeed. I put my LTO drive in the fuse box.

As overseeing backing up, from various optical media to disk, just don't use the optical stuff!

This was a huge international conglomerate, doing CD backups for decades. Now it turns out these precious backups only worked 96-98% of the time. Terrible stuff.

Actually 96-98% is not great but not terrible if you're employing some kind of parity scheme across multiple discs. It just means 1 in 20 (or 1 in 10 to be safe) extra discs in the mix.

I just checked using $ sudo smartctl -a /dev/nvme0n1

    Percentage Used:                    2%
    Data Units Read:                    7,173,143 [3.67 TB]
    Data Units Written:                 22,666,414 [11.6 TB]

That's after about 2 years of use. I think SSDs can take quite the beating nowadays.

The oldest NVMe SSD I have at home is a Samsung 950 Pro (the 256 GB version!) which I bought in late 2015 IIRC (and put on a ASUS Z170-A mobo, that already had a NVMe slot) and which has been in use that whole time (but mostly light desktop use):

    Percentage Used:                    27%
    Data Units Read:                    48,801,760 [24.9 TB]
    Data Units Written:                 84,590,914 [43.3 TB]
    Power Cycles:                       228       <-- only 228 power cycles in 11 years, that's about 17 days uptime every time I think
    Power On Hours:                     37,153    <-- not sure about this one, this comes out at about 9 hours / day of uptime

And after 11 years it's still going strong!

Now it's not on my main computer anymore: I'm rocking a WD-SN850X (recommended here on HN when it came out) but the old Samsung 950 Pro is on the desktop computer my wife uses daily (and she WFH).

> I think SSDs can take quite the beating nowadays

For regular use definitely. In my servers I've got ZFS in mirroring though: you never really know when a drive is going to RIP.

Percentage Used: 0% Data Units Read: 15,235,390 [7.80 TB] Data Units Written: 33,573,616 [17.1 TB] Host Read Commands: 107,051,408 Host Write Commands: 496,391,879 Controller Busy Time: 455 Power Cycles: 938 Power On Hours: 13,189

Not bad ;)

    Percentage Used:                    13%
    Data Units Read:                    686,519,123 [351 TB]
    Data Units Written:                 358,581,477 [183 TB]

4 years of gaming :P.

7 years of use :D

    Percentage Used:                    3%
    Data Units Read:                    77,182,320 [39.5 TB]
    Data Units Written:                 83,995,559 [43.0 TB]

You write 3x more than you read? Seems like a strange access pattern. Maybe something is going haywire with logging?

Could be a log ingestion server or surveillance camera recorder.

They can yes but they do need to be powered at least once a year or they'll lose data too.

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...

Thanks, I read your article and my main reaction is that I'm saddened by the loss of data on those few unreadable discs. I hope it wasn't something you'll need to dig up in a few years.

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.

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.

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.

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.

They definitely are mysterious, but to me, magneto-optical media (such as MiniDiscs) take the cake.

Written magnetically (while heated by a laser), read optically (by a much weaker laser), and somehow all of that fit into a pocketable player powered for 10+ hours by a single AA battery!?

Unlike rewritable optical media, opto-magnetic storage also seems to have effectively unlimited rewrite cycles. It's a real shame they never became a popular data storage option, mainly due to Sony's paranoia stemming from also owning a huge music and film division.

Music-wise, lossy compression takes place via a proprietary codec (ATRAC). It isn't viable for data storage (neither was CDR(W)). Trust me, I had data loss due to all of these. Just use LTO with some parity data.

Not sure I understand, are you saying that you were using MiniDiscs or other MO media and were experiencing bit rot?

Making ATRAC the exclusive and mandatory codec for MiniDisc Audio was another typical unfortunate Sony move but in my view doesn't discredit the strengths of the physical storage medium.

Honestly, I wasn't being specific. I like a specific music genre, and within this music genre some unique content was saved to DAT and Minidisc. The DATs were lost, and so the only available medium has been based on Minidisc.

So your data only survived in a lossy format, because MiniDisc, but it did survive, also because MiniDisc? The quintessential MiniDisc experience :)

That's the thing. It wasn't me. Someone in the scene received it from original artist, and he put it on minidisc, this was end 90s. Those who appreciate the genre, love these hidden gems, but it is only available as lossy due to minidisc (and MP3). Back then, FLAC did not yet exist, but CD did. Regarding MP3, codecs (including LAME) improved a lot over the years. The overal quality of the LAME presets, nowadays (and this has been tge way for more tgan a decade), is good enough compared to lossless, something double blind tests confirm.

In this case, I believe you are right: I don't think the data would've survived without minidisc. But in other circumstances where the user did not know minidisc is lossy?

In the end, a lot of these hidden gems have been (re)released because lost tapes (and, I suppose, HDDs) were found which is neat.

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.

I guess the drives just cost too much and so zip won until flash drives took over.

I saw zip adoption before CD-RW, flash drives much later. But maybe it depended on how much data you needed transferred. Early flash drives were much smaller than CD/DVD.

I miss my first 128mb usb drive. Cost nearly $40 and survived a dozen wash cycles accidently left in my pocket all the time. Now days I've got 64gb drives that seem to shit the bed after a few rounds as a Live-USB linux environment. At least they only cost $15 or less.

People who still remember Zip drives! In college I did tech support for Iomega. It was an interesting time ;)

>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!

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.)

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.)

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.

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.)

> You could also use an OS that doesn't tend to have dodgy updates that brick your system, such as most Linux distro.

I haven't done it recently but back when I was learning Linux, I definitely bricked my fair share of installations updating and installing things.

It was probably fixable to a more experienced person but it wasn't to me.

Linux is a lot of things but brick-proof for novice users isn't one of them.

It has gotten a lot better from what I can tell, though that is just based on what I see others struggle with (or not struggle with as may be the case).

I can't judge this directly (I'm in way too deep, running Arch etc), I first started using Linux seriously in 2004, stopped using Windows except for gaming by 2006, and touched it less and less over the years. I have not used Windows 11 at all.

> if you are stuck with such software

kvm-qemu, windows image, block network access to the windows update servers, problem solved?

I never managed to get Fusion 360 running reasonably on Linux, in the end I switched CAD software. It really needs some sort of reasonable OpenGL support (or maybe DirectX, I forget which it was). And it doesn't work under wine, it did at some point but then it stopped. Cloud connected software, so you can't just run an old version.

Maybe if you had a second GPU and forwarded it to the VM? Not willing to spend that extra money, and it would only work on my desktop, not my laptop.

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.

Yeah it still has some annoyances though. Still telemetry crap, still forced updates (you can turn them off with a GP just like on regular but still, I didn't expect it on LTSC). It even tries to get you to sign in with a Microsoft account. It's an improvement but not as I expected.

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.

For a nuclear option, delete C:\windows\system32\wua* or move these files somewhere else.

The nuclear option is linux

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.

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.

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.

The same site has an article on that: https://goughlui.com/2024/07/28/tech-flashback-intel-optane-...

Retention issues are a bit worrying.

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?

There may be hope for something like that happening, conceptually at least. Underlying technology is different, though:

https://www.heise.de/en/news/Memory-chip-company-FMC-keeps-w...

https://www.ferroelectric-memory.com/technology/

My kingdom for a MicroSD card with Optane inside.

I used to work for a vendor who wrote the drivers for iTunes CD burning, I actually built a in house tool that could take multiple machines with 8 drives each and test our driver by burning to CD-R, DVD-R, DVD-RW, etc... and read the data back to ensure no regressions in our drivers.

Reason for testing so many drives is that when it comes to the real world, a lot of drive manufacturers cut corners and didn't follow standards, so we had a growing list of "work arounds" that we would validate. Every manufacturer would send us their drives to validate, we had a huge closet with shelves floor to ceiling of different drives.

Was a cool internship out of high school an forever thankful that I got it. Even if it's my most boomer skillset.

Couple of main things that post are 100% correct, the brand of media does matter. We actually had specific media we would recommend to the DOD for maximum stability. Second of all faster media always performs worse for archival purposes, and burning faster will result in more errors as well.

For testing we had a specific media for each type we found could be used for 25x tests reliably, but I don't remember the brands/type. We would basically load them once a year since we did a full verification every few weeks.

I always wanted to like DVD-RW and CD-RW. But I just couldn't.

Cost. A couple dollars per disc, versus a couple pennies per disc for the one-time use.

Easily scratched.

They were slow. You could use a Syquest or Iomega 1GB drive, boot off it, etc. Basically as fast as a hard drive was.

They were compatible until they weren't. Plenty of issues trying to read those things on other computers.

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.

Why did the author have to do all this hacking around with screenshots? Back in the day, you could query any window for its title/text/buttons and send events to the buttons directly. Is this not the case in Windows any more?

Apart from win32 itself, most frameworks (everything from Java Swing to Electron) just use the win32 API to draw pixels to the screen and don't integrate with the window hierarchy.

Would be interested to know if automating rewrites makes the disc run hotter which affects the disc lifetime physically as opposed to writing it and then removing it which cools it off (but may cause physical wear and tear from handling it). Does heat play a role in degradation or whether it’s the opposite and helps it in some way.

I wish there were dual layer RW discs. Afaik some were made but they never hit the consumer market in the end

What a great analysis! 20 years ago, this would have saved me a lot of headache/anxiety and a moderate amount of pocket money :)

With USB drives today being large and popular, what are the main uses of DVD-R's and DVD-RW's, in your experience?

I think what we are all really questioning about is: how many times can it be rewritten in Rust?

No, this is optical media, rewriting in rust only pertains to magnetic storage.

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

There was actually only a short period of time when only write-once DVDs existed. By 2005 just about any computer DVD drive you could buy supported all combinations of {CD,DVD}±{R,RW} that existed. Blank RW disks were, of course, more expensive than R's, though.

DVD±RW was super useful for passing around files in a period where flash drives were expensive. My high school photo journalism club used them a lot to pass around photos and documents, a couple days later they'd get ingested into the PC in the club room, erased, and put back on the pile for you to bring one home.

I don't ever think I had one fail to write

Yes, they were present and not much expensive than standard ones. However, the issue was that they encountered problems/data loss after few rewrites.

Except that according TFA they can actually last thousands of rewrite cycles.

Indeed, I posted it because my experience was different, perhaps due to my DVD writer or my settings. After 10- 15 rewrites, I almost always encountered issues

Very timely article! :)

Thank you. Now I can rest easy knowing that my 500 stack of unused DVDRWs sitting in my cupboard that I got for so cheap at Fry's is going to last me the rest of my life.

Looks like a stale article from 2006.

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