Sony is about to start selling the industry’s first 128 GB write-once BD-R XL optical media. The discs will also be the first quad-layer BDXL media formally aimed at consumers, but bringing benefits to professionals that use BDXL today.

Although the general BDXL specifications were announced back in 2010 for multi-layered write-once discs with 25 GB and 33.4 GB layers, only triple-layer BDXL discs with a 100 GB capacity (generally aimed at broadcasting, medical, and document imaging industries) have been made available so far. By contrast, quad-layer 128 GB media has never seen the light of day until now.

As it turns out, increasing the per-layer capacity of Blu-ray discs (BDs) to 33.4 GB via a technology called MLSE (Maximum Likelihood Sequence Estimation) was not a big problem, and most of today’s BD players and optical drives support the BDXL standard. However, increasing the layer count to four while ensuring a broad compatibility, signal quality across four layers, yields, and some other factors slow downed release of 128 GB BDXL essentially by eight years.

In a bid to build a viable quad-layer 128 GB write-once BDXL disc, Sony had to design three new materials. First, the company had to create a new recording alloy that would provide the right combination of reflectance and transmittance to ensure that the layers can “reflect” data bits when needed while allowing the 405nm laser to pass through them when another layer is accessed. Then, Sony had to develop a new inter-layer material (called dielectric) that would also be able to transmit light waves. Finally, because with four layers the first one has to be located closer to the disc’s surface, Sony had to design a new protective coating for the media.

Sony will start shipments of its BD-R XL 128 GB media on the 10th of November. Single-disc packages (BNR4VAPJ4) will retail for ¥1,500 ($13), a pack of three (3BNR4VAPS4) will cost ¥3,900 ($34), whereas a pack of five (5BNR4VAPS4) will be priced at ¥6,000 ($53). The discs should be compatible with drives supporting the BDXL spec, though a firmware update may be needed regardless.

Related Reading:

Sources: Sony, PC Watch,

Comments Locked


View All Comments

  • PeachNCream - Friday, November 9, 2018 - link

    Interesting, but the market for write-capable optical media is probably not as big as it was when the first CD-Rs were released since there are lots of other options for high capacity "sneaker-net" storage around.
  • edzieba - Saturday, November 10, 2018 - link

    It's getting a decent amount of interest for medium-term (i.e. non-archival) cold-stoarge, as you can grab a specific file from an optic disc far more quickly than you can spool along a tape, even with the added delay of loading the drives.
  • Tams80 - Saturday, November 10, 2018 - link

    Not as big, but CDs were THE format back then. There's still a sizeable market, albeit much smaller. Optical storage also has price on its side (just) and for long term storage is much more reliable.
  • LagnusDwanderer - Wednesday, October 2, 2019 - link

    Still quite relevant tech. I will be buying and using these to create a personal and family archive. I also think companies might turn to using this tech in a different form for data archiving as the M-disc form of it can last for 1000 years.. more if store in inert conditions I suppose. Think big sheets of crystal that sit as slides with interlocking prism which direct the laser to specific points using IBMs optical chip tech.

    Imagine a time capsule filled with helium, a 100 disc spool, rollable solar panels, rollable eink colour screens, SoC on kapton tape computers. 1 disc on rebooting humanity from the stone age to a "green tech" age in 10-30 years, 99 discs for everything else from science to hobbies, flash cards for establishing language picture maps and something like that tablet Paul Atriedes had in Dune which was instructing him using visual, audio and narrative slides (burrow bush..).

    Every now and then, there are geniuses who grew up in complete isolation with no outside influence and invented their own complete and advanced engineering mathematics from scratch. So seal the tube with an equation based locking mechanism.. so that tube is only for capable minds to open.

    Also break it up into stages, so
    1 stage math lock
    2 stage language lock
    3 stage ethics lock
    4 stage culture lock
    5 stage machinist lock, machine a specifically shaped key
    6 stage electricity lock, upgrade the key with magnetic inserts to power the lock and push the button
    7 stage tech lock, use the properties of the key, electrical lock to decipher a digital pattern which is a decryption key
  • xiaohongshu - Sunday, May 1, 2022 - link

    Mind = Blown
  • frenchy_2001 - Wednesday, November 14, 2018 - link

    They are only 50% of the price of a 128GB MicroSD.
    write once vs write many
    bad access time vs flash
    not sure about read/write bandwidth, but the SD is no slouch there either...
    not sure which one retains data better (burnable CDs/DVDs were actually pretty bad, most of them with an expected shelf life after burn of ~5 years top if kept in a dark and dry environment)
  • cb88 - Monday, June 10, 2019 - link

    A flash cell is worse if anything... over time the charge in a flash cell does degrade to the point that it can't be read. Flash should never be used for anything other than short term storage.

    If you want to archive anything on disc, you should be using M-DISC Blurays... they are about twice as resilient as regular discs theoretically good for 1000 years stored in the dark at least that's what they advertise.
  • xiaohongshu - Sunday, May 1, 2022 - link

    What about m-disc archival reliability?
  • deusexaethera - Wednesday, September 25, 2019 - link

    Optical discs are no longer the medium of choice for Joe User to carry around his stash of funny cat videos, but they are still widely used in professional IT, government, and anywhere else where data security is a concern. If you have a job where you're not allowed to talk about the work you do, there is almost certainly a security officer who checks all the media you bring in to check for malware, and checks all the media you take out to ensure it doesn't contain any new data that it didn't have when you brought it in. As datasets continue to grow in size, there is an increasing need for high-capacity W.O.R.M. media to transport that data in a secure manner.
  • iwod - Friday, November 9, 2018 - link

    Were there any PS4 / Pro Games that ever needed two BD? i.e 50GB ( Assuming all PS4 BD are 25GB )?

Log in

Don't have an account? Sign up now