🚀 go-pugleaf

In article <28719@cup.portal.com>, tms@cup.portal.com (Alexis TMS Tatarsky) writes:
> Sometime back I requested information regarding high capacity backup
> media.  Thanks to all who responded.
> 
> The majority of the respondents pointed me in the way of Exabyte 8mm 
> technology.  Some pointed me towards the R-DAT technology.  Those who
> were using the 8mm technology were, for the most part, happy whith their
> purchase.
> 
> The R-DAT proponents mentioned that this technology would surpass the 8mm
> technology in the near future.  I believe this to be true.  For one, only
> one manufacturer (Exabyte) has gotten into the 8mm game.  Also, many computer
> manufacturers (HP  for instance) are going with R-DAT as standard product.

  The key to this lies in the words "R-DAT proponents".  Now, you wouldn't
  expect these people to tell you that a competing technology was better than
  their own, would you?  Technically there is only one manufacturer of 8mm
  drives, however, Kubota of Japan manufactures ~60% of all 8mm drives made
  under license to Exabyte.  They also have the licensed ability to sell to
  the Pacific rim.  One of the reasons that there aren't more players in the
  8mm market is that Exabyte owns patents on most of the technology that makes
  the drive suitable for data storage.  R-DAT is a CONSUMER based product that
  still uses much of the audio recording hardware and encoding schemes in the
  data storage device.  One of the penalties of this is the comparitively high
  probability of significant capacity loss on the 4mm device if error
  correction has to be invoked (as it inevitably will: this is, after all,
  tape we are talking about).  For the record, Exabyte has licensed the DDS
  format (the HP/Sony format) and could, due to the ready availability of the
  hardware, bring a 4mm product to market in a very short time should it prove
  to be warranted.  The 4mm vendors would have to spend a large amount of time
  and money to develop an 8mm device because it would have to be designed from
  the ground up and, with Exabyte's huge lead in the marketplace, the catch up
  game is probably out of reach for them.  As for the reason that HP is "going
  with R-DAT as a standard product", they jointly developed both the drive and
  DDS format with Sony so one would expect them to use it.

> My question is why???  8mm has a higher capacity, is faster, and as far as I
> know reliable (even though early Exabyte units proved extremely unreliable).
> ok
> Any insight as to why R-DAT is technologically the way to go would be extremely
>  appreciated.

  8mm does indeed have a capacity and speed advantage over R-DAT drives and
  that lead has recently been extended with the announcement of a 5Gb drive
  which will be read AND write compatible with the current product and will 
  transfer data at 500Kb/sec.  As to the liklihood that R-DAT will surpass
  8mm technology, it would have to be a very stretched definition of "surpass"
  to fit.  The 4mm format is currently at saturation and the data is actually
  written so that data from adjacent tracks overlaps.  The azimuth of the
  adjacent tracks is different so that the drive can line up on the correct 
  track.  The only way that they can increase capacity is via compression,
  longer (and therefore thinner) tapes, or a combination of the two.  These
  two alternatives can also be applied to the 8mm format as well but, because
  the 8mm tape format is only at about 70% saturation with the 5Gb model, I
  would expect to see further capacity increases on it without using either.
  It would seem unlikely that R-DAT will surpass 8mm in capacity.  Right now,
  R-DAT is the "new and sexy" technology and it will be interesting to see how
  well it stands up in the real world of data storage as the number of drives
  shipped increases.  I personally think that the two will coexist in the
  storage marketplace with the R-DAT product filling a niche below the 8mm
  device.


  Guy McConnell                      |  The above is my opinion and may not
  Intergraph Corp.                   |  reflect the opinion of Intergraph.
  Mass Storage Peripheral Evaluation |
  Tape Specialist                    |