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Toshiba Unveils World's First FC-MAMR HDD: 18 TB, Helium Filled
Toshiba this week announced the industry's first hard drive featuring flux-control microwave-assisted magnetic recording (FC-MAMR) technology. The new MG09-series HDDs are designed primarily for nearline and enterprise applications, they offer an 18 TB capacity along with an ultra-low idle power consumption.
The Toshiba MG09-series 3.5-inch 18 TB HDD are based on the company's 3rd generation nine-platter helium sealed platform that features 18 heads with a microwave-emitting component which changes magnetic coercivity of the platters before writing data. The HD disks are made by Showa Denko K.K. (SDK), a long-time partner of Toshiba. Each aluminum platter is about 0.635 mm thick, it features an areal density of around 1.5 Tb/inch2 and can store up to 2 TB of data. The MG09 family also includes a 16 TB model which presumably features a lower number of platters (based on the same performance rating).
Previously:
Toshiba Will Adopt Western Digital's Microwave-Assisted Magnetic Recording Approach for Hard Drives
Toshiba Roadmap Includes Both MAMR and HAMR Hard Drives, as Well as TDMR and Shingles
Western Digital Releases New 18TB, 20TB EAMR Drives
(Score: 3, Funny) by Anonymous Coward on Sunday February 21 2021, @08:46PM (8 children)
>> areal density of around 1.5 Tb/inch2 and can store up to 2 TB of data
And the rest of the space on the 3.5" disk is used for... ?
(Score: 0) by Anonymous Coward on Sunday February 21 2021, @08:58PM
Spindle, etc.
(Score: 0) by Anonymous Coward on Sunday February 21 2021, @09:04PM
8 bits per Byte
(Score: 0) by Anonymous Coward on Sunday February 21 2021, @09:05PM
The flux capacitor.
(Score: 4, Insightful) by takyon on Sunday February 21 2021, @09:14PM (3 children)
https://en.wikipedia.org/wiki/Heat-assisted_magnetic_recording [wikipedia.org]
(1.5/8) * (π * (3.5 / 2)) * 2 [double-sided] = 3.6075 TB
There is the spindle in the center that doesn't count, and probably some unusable area at the edges of the platter, and maybe some capacity reserved for error correction.
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(Score: 1, Informative) by Anonymous Coward on Monday February 22 2021, @03:27AM (1 child)
IIRC, typical 3.5" platters have around 75% usable area, mostly due to the significantly reduced transfer rates near the spindle. The outer track will be as close to the edge as they can manage. The 5:4 or 10:8 encoding required for clock recovery is the next biggest user at 20%, and isn't really negotiable. Sector gaps, and timing headers should be the next largest consumers, and reducing them was the main motivation for the move to 4k sectors. That more than paid for the increased space requirements needed for ECC. Reserve sectors only take up a tiny fraction, typically only a couple hundred sectors in total. It is solid state drives require a large reserve fraction due to their high wear rate.
(Score: 0) by Anonymous Coward on Monday February 22 2021, @04:56AM
That info is a little out of date. The usable area is a bit over 87%, thanks to things like ZBR and the encoding is more efficient than 8b/10b. And there are more reserve sectors in HDDs than you realize. They need them during production, testing, and low-level formatting to correct for manufacturing errors that will inevitably slip in without having to bin.
(Score: 2) by takyon on Monday February 22 2021, @04:13AM
Forgot to square the radius, but the real question is what % of the circle is usable.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 1, Flamebait) by Snotnose on Sunday February 21 2021, @10:23PM
Pron starring your mom.
When the dust settled America realized it was saved by a porn star.