Slashdot Mirror
Holographic Storage Crams in 0.5TB Per Square Inch
An anonymous reader writes "VNUNet is reporting that a company called InPhase Technologies claims they have successfully recorded 515GB of data per square inch to capture the record for highest data density. From the article: 'InPhase promised to begin shipping the first holographic drive and media later this year. The first generation drive has a capacity of 300GB on a single disk with a 20Mbps transfer rate. The first product will be followed by a family ranging from 800GB to 1.6TB capacity.'"
I was looking for some details on the storage mechanism and specifications of data decay, reliability and such, I didn't see anything on that. Will normal error correction be sufficient for such a device, or does it make sense to use the same disk to write every bit of data onto it more than once in different locations, say 3 times alltogether and when reading, compare the bits and chose the value that happens at least 2/3 times? Will data decay on this media any faster or any slower than on a normal magnetic disk?
You can't handle the truth.
For high output data rate, one must read holograms with many pixels per page in a reasonably short time. To read a megapixel hologram in about 1 ms with reasonable laser power and to have enough signal at the detector for low error rate, a diffraction efficiency around eta = 3 × 105 is required. To write such a hologram in 1 ms, to achieve input and output data rates of 1 Gb/s, the sensitivity for this example must be at least S'eta2 = 20 cm2/J.
Since this hologram was retrieved using a readout pulse of 1 ms, this experiment implements the optical signal (but not the subsequent fast electronic readout) of a system with a readout rate of 1 Gb/s.
They are using optical storage technology, not terribly dissimilar to CD-R and DVD-R technology.
So, how well do their disks stand up against bit-rot?
More promises, no product move along.
Back in 2000 or 2001 slashdot had a story about a company called C3D (or CDDD which was their stock ticker, website was http://www.c-3d.net/). This company promised 1TB and higher density discs with insane transfer speeds because it was storage...in 3D. They showed a few discs (CD sized) and a reader which were supposedly a prototype of some sort at trade shows. All of this ran their stock up quite a bit. They were promised to replace DVD's in a few years, and eventually hard drives. There was also this credit card device (10gigs) which was rewritable (?), which was to replace traditional hard drives in notebooks.
Deadline after deadline passed, the stock slowly declined ($60 a share was the norm in 2000) due to the market conditions in 2001, eventually causing it to be delisted from the NASDAQ (has a value of $0.01 a share). Rumor has it that the company was founded/owned/something by a former Israeli/Soviet general (the company wasn't located in the US), and that there never was a product (all demos were faked).
How do I know this? I was the fool who bought the stock when it was $20 a share, watched it rise up to $66, and fall to nothing. I believed before and it cost me a decent amount of money.
Holographic media has been a scam before and it'll be one until there is a box with a price tag in a store. Even then, I would be cautious about buying it.
"Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway."
...or whatever the exact quote is, as I couldn't find a reliable source for it.
~ Andrew Tanenbaum
You *really* must have meant 1.6 *TB* instead of GB. Then your numbers would make sense.
1.6 GB * 8 * 1024 = 131107.2 Mb - megabits in 1.6 gigabytes
131107.2 Mb / 20 Mbps = 655.36 s - seconds to read at 20 megabit per second
655.36 s / 60 s = 10.92 min - convert to minutes
At 20Mbps, it would take you 4.855 days to read a terabyte, which is pitiful for local storage. (1.6TB would be 7.77 days, or the almost 8 days in the parent post.) Even at 20MBps, that is still 14.56 hours for 1 TB, which is far too slow.
This might work as a backup medium for archiving, as long as it was suposed to be 20 megabyte/s instead of megabit. Many tape systems are right around the 20MBps mark, however there are solutions out there that archive over 100MBps.
The Holographic model of Data Storage isn't really that "un-tested". While we might not know how it works (the under-the-hood understanding of it) -- we knmow that it does -- the Human Brain stores memory in a holographic model (read the Holographic model of the brain as proposed by Dr. Karl Pribram) and infact a renowned physicist by the name of David Bohm suggested such a medium for the whole of the universe itself. But that aside -- the beauty of a hologram is in it's ability to retain all of the data it stores even though the physical medium itself might be disrupted/reduced somehow. IIRC, the concept goes like this -- you can cut a hologram into smaller pieces -- but each of these would retain the whole image. There is possibly a certain level of "differentiation" that needs to happen before the validity of the data gets compromised...
What would happen if we invested heavily into developing factories to manufacture these, stuffed them into cheap durable nintendo style units, preload every book indexed by the google book project and every song we could lay our hands on and distributed them to every man, woman and child on earth?
-1 Uncomfortable Truth
As the subject line says, I'm very very worried. I mean this from a "1984" standpoint.
We've already read stories about how our past activities on the Internet (news groups, blogs...etc) can catch up with our future in a very bad way. With storage getting cheap and more abundant, I fear that giant archives of public data will be collected daily and stored for hundreds of years...all ready to be pulled for review later. Any place, at any moment, digital video of you recorded in public can be data-mined using facial feature algorithms to track your history of where you went, when, and for how long.
While such technology will certainly be available in the UK, there is nothing against US law from preventing it happening here. Homeland Security, Patriot Act...bla bla bla. It's just a matter of time when terabytes are cents on the dollar.
Life is not for the lazy.