Feeds

Seagate REJECTED buyout offer for Virident – analyst

Go ahead, WD, pay half a billion for it... we have some top secret tech to get on with

Top 5 reasons to deploy VMware with Tegile

Hard drive supremos Seagate had first refusal on buying out enterprise flash startup Virident – and turned it down, leaving WD free to snap it up for $685m.

This little bombshell burst forth from a report on a Seagate Analyst Day by Stifel Nicolaus' chief, Aaron Rakers. A second juicy nugget was that Rakers thinks there were other bidders as well as WD for Virident.

Rakers' report contained yet another storage revelation on top of those two: Seagate are adopting a little-known disk drive recording technology called Two Dimensional Magnetic Recording (TDMR).

Seagate will also, says Rakers, ship a 3D NAND SAS-interface SSD in the first half of 2014. El Reg's storage desk believes this will use Samsung 3D V-NAND chippery.

Just to put the cherry on that nicely iced cake, Seagate is developing two enterprise SSD controllers internally.

TDMR

Seagate sees hard disk drive recording technology having an intermediate Two Dimensional Magnetic Recording (TDMR) technology being used soon, before moving to HAMR (Heat-Assisted Magnetic Recording). TDMR sounds like a stop-gap, similar to shingling (SMR), as it will only produce a 20 per cent or so increase in areal density over SMR.

The company said nothing at all about TDMR when it introduced shingling and HAMR to journalists at a briefing in August. It says HAMR product integration could start in 2016, by which time TDMR product integration would be under way.

TDMR "involves improved signal-to-noise ratio" according to Rakers. Searching for TDMR info on Seagate's website gets you zip, nada, nothing – at the time of writing, anyway.

Googling "Two Dimensional Magnetic Recording" gets you lots of papers from data recording conferences. An HGST one (PDF, 59 pages), for a presentation in October 2010 to the IEEE Magnetics Society's Santa Clara Chapter, positions TDMR as an associated technology for shingling.

It states:

  • Two-Dimensional Magnetic Recording (TDMR) = Shingled Write + 2D Readback
  • Two-Dimensional Readback implies either several revs of latency, or a read head with three or more immediately adjacent sensor elements.
  • In 2D-readback, a complete ‘picture’ is built up from multiple tracks - ITI (Inter-Track Interference) is no longer destructive. ITI contains information about the data that powerful detectors can extract
TDMR diagram

TDMR diagram. (Y. Shiroishi, Intermag 2009, FA-01)

TDMR is an extension of shingling technology. The 2-dimensionality comes from the read signal information being stored along the track - dimension 1 - and across tracks, along the radius of the disk - dimension 2. This, you would think, would slow writing in the same way as shingling does, but researchers suggest flash-based caching and buffering could counteract that.

It seems to the storage desk at El Reg that it is the combination of SMR and TDMR that is Seagate's response to HGST's helium-filled drives, which have more platters and heads than air-filled drives.

Seagate reckons SMR could generate a 20TB HDD with a 1.2Tbit/in2 areal density. HAMR could produce up to 5Tbit/in2 areal density; that's the big jump that will enable HDDs to regain some sort of parity between their capacity growth and data storage growth. ®

Beginner's guide to SSL certificates

More from The Register

next story
It's Big, it's Blue... it's simply FABLESS! IBM's chip-free future
Or why the reversal of globalisation ain't gonna 'appen
'Hmm, why CAN'T I run a water pipe through that rack of media servers?'
Leaving Las Vegas for Armenia kludging and Dubai dune bashing
Microsoft and Dell’s cloud in a box: Instant Azure for the data centre
A less painful way to run Microsoft’s private cloud
Facebook slurps 'paste sites' for STOLEN passwords, sprinkles on hash and salt
Zuck's ad empire DOESN'T see details in plain text. Phew!
CAGE MATCH: Microsoft, Dell open co-located bit barns in Oz
Whole new species of XaaS spawning in the antipodes
AWS pulls desktop-as-a-service from the PC
Support for PCoIP protocol means zero clients can run cloudy desktops
prev story

Whitepapers

Cloud and hybrid-cloud data protection for VMware
Learn how quick and easy it is to configure backups and perform restores for VMware environments.
A strategic approach to identity relationship management
ForgeRock commissioned Forrester to evaluate companies’ IAM practices and requirements when it comes to customer-facing scenarios versus employee-facing ones.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.