Talk:Heat-assisted magnetic recording

Correction

I understand that Fujitsu might have been WORKING with the technology in 2006 but I think the report that they developed it is not correct. Seagate had been working on demoing the technology back in 2002 as reported in this article. —Preceding unsigned comment added by 24.65.241.130 (talk) 21:23, 14 May 2010 (UTC)[reply]

MiniDisc?

Shouldn't Sony MiniDisc be mentioned in this article? Jeh (talk) 22:16, 17 August 2014 (UTC)[reply]

No, because it uses magnetically assisted optical recording (M-O) which is read optically. It's completely different from HAMR. 83.104.249.240 (talk) 17:42, 5 July 2016 (UTC)[reply]

You're mistaken. When writing a recordable minidisc the laser is not modulated with the bits; the magnetic field is. The laser is used to heat the material past the Curie point, making it easier to flip the magnetic domains. If that isn't Magnetic Recording, Heat Assisted, i don't know what is. In fact it seems to exactly match the description here. Playback is done optically but it's still reading magnetic patterns, hence it is reading a magnetic recording. Jeh (talk) 18:33, 5 July 2016 (UTC)[reply]

...added a ref, which it took me all of one Google search to find, on the first page of hits. I'll clean up the cite tag later but this will address your tag. Jeh (talk) 19:00, 5 July 2016 (UTC)[reply]

Energy usage.

If this thing is using heat to increase data density, doesn't that mean that the drive uses a lot of energy to produce that heat? How do the numbers compare with a non-hamr drive? I imagine this would be a bigger deal in enterprise server racks, where heat is already a huge problem. — Preceding unsigned comment added by 50.157.226.255 (talk) 01:50, 23 December 2014 (UTC)[reply]

The lasers only need to heat a tiny area, so will use almost no power. [1] talks about a 150mW power usage laser, which is non-consequential compared to the ~5W total power usage of normal hard disks. Thue (talk) 04:01, 23 December 2014 (UTC)[reply]

Why not just optical ?

Once a laser is added, why not scrap the magnetic part and use light-only process ?

Of course they know what they are doing, but we don't so reasons should be explained. After all, it is similar to Magneto-optical drive that fell into disuse.Musaran (talk) 07:45, 21 July 2015 (UTC)[reply]

Because optical discs are slow to write. The technology discussed in this article is magnetic recording that's assisted by a raised temperature. It isn't optical technology at all - other than that a laser is used as the finely focused heat source. HAMR disks are read magnetically; M-O disks are read optically. 83.104.249.240 (talk) 17:29, 5 July 2016 (UTC)[reply]

Impact on head design & performance ?

Since writing is now determined by the heating focus, this should remove heavy constraints on head design and allow some other improvements.
OTOH, the added weight is bound to slow head movements.

This should be covered. Musaran (talk) 07:50, 21 July 2015 (UTC)[reply]

Don't assume there will be any added mass. The laser doesn't have to be physically anywhere near the head. The optics could be built into the hub of the actuator and mirrors or light-pipes used to get the light where it's needed. 83.104.249.240 (talk) 17:39, 5 July 2016 (UTC)[reply]

Loses coercivity or gains coercivity

Your text states: "A tiny laser within the hard drive temporarily spot-heats the area being written, so that it briefly reaches a temperature where the disk's material temporarily loses much of its coercivity." I don't suppose you actually mean that the material temporarily gains coercivity. In order to write at a higher areal density the material must become briefly more "coercive." — Preceding unsigned comment added by Wikitacky (talk • contribs) 16:32, 24 December 2019 (UTC)[reply]

Article is full of predictions. What actually happened?

The article describes how e.g. Seagate would ship these drives in 2020, written in 2017 and 2019. Did that happen? Where are newer references, such as to actual shipping products? Let's fix the tense from future to past, if it actually happened. -- Gnuish (talk) 08:44, 16 February 2022 (UTC)[reply]