The Evolution of HDDs in the Near Future: Speaking with Seagate CTO, Mark Re
by Anton Shilov on July 6, 2016 2:00 PM ESTTwo-Dimensional Magnetic Recording Due in 2017
Two-dimensional magnetic recording (TDMR) is a yet another technology that should help to increase areal density and this is something that Seagate is investing in. The manufacturer believes that TDMR helps to increase areal density by 5% to 10%. Plans were announced several months ago and during the conversation with Mark Re, it was confirmed that Seagate was on track to release its first commercial TDMR-based HDDs in 2017.
TDMR technology enables makers of hard drives to increase the areal density of HDD platters by making tracks narrower and pitches even smaller than they are today. While it is possible to minimize the writer (a part of an HDD's head that writes data), reading becomes a challenge. As magnetic tracks become narrower, they start to affect each other, an effect called magnetic inter-track interference (ITI). This means It becomes increasingly hard for HDD heads (readers) to perform read operations. To mitigate the ITI effect of very narrow tracks, two-dimensional magnetic recording technology uses an array of heads to read data from either one, or several nearby tracks (a method described in several scientific publications). This improves the signal-to-noise ratio delivered to the controller. Several readers enable HDD controllers to determine the correct data based on input from several locations, which implies the need for powerful controllers. More importantly, a number of read heads will be a benefit for HDDs featuring HAMR in the future: heat-assisted recording improves the write process, whereas multiple readers improve the read process. We are also told that with relevant programming, hard drives featuring an array of readers per head can increase the performance of HDDs. This will clearly not make the new hard drives as fast as SSDs, but it will help Seagate’s customers (particularly in the SAS space) to increase the performance of their storage devices. Right now, Seagate does not talk about its plans to use multiple readers in commercial drives because such products are several years out, but considers this a possibility.
Seagate confirmed that TDMR lets HDD makers to increase areal density by up to 10%, which is a noticeable amount compared to typical PMR platters. However, additional capacity does not come free in this case when it comes to computing. An array of heads increases bandwidth requirements for the controller as well as the amount of information that the chip needs to process. As a result, the whole TDMR platform becomes generally expensive: it features multiple arrays of heads, new platters, new motors as well as new controllers. This is why Seagate plans to use it for server applications first sometime in early 2017. Seagate did not confirm whether such HDDs would use both TDMR and helium, but said that virtually all technologies could be mixed and matched to build the right solution for every possible application. Keep in mind that these are plans which are subject to change.
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Ushio01 - Wednesday, July 6, 2016 - link
I wonder how much of this will ever reach market? as SSD's take over ever more of the storage market the remaining HDD manufacturers will be required to spend ever more on R&D while dealing with shrinking revenue.DanNeely - Wednesday, July 6, 2016 - link
The consumer HDD market is slowly imploding, but while it's roughly half of all drives sold that's not where the money is. The Enterprise HDD market is doing better. Sales are down a bit; but while Seagate/WD/Toshiba don't break the two segments of enterprise drives out, it's probably from SSDs chewing into 10/15k drives in servers not the high capacity 3.5" drives used for bulk storage. Seagates comments about the next gen of 15k drives potentially being the last tends to back this up, since they're talking about multiple generations of other drive types.Bulk data storage will stay with spinning rust until the price per GB crosses over in SSDs favor. Estimates I've seen on that a year or so ago were looking at 2025; but there's a fair amount of speculation there since the results of a half dozen generations of tech in each platform are somewhat speculative.
Anato - Wednesday, July 6, 2016 - link
That patent [1] is clear example how current patent system is out of control and not useful to society at large. Short recap, patents original idea was to give temporal monopoly to inventor who disclosed his invention. There was no right to own anything you invented, but it was seen that disclosing the invention would ultimately benefit society who, after temporal monopoly, could use the invention.Now opposite is true, there is nothing useful disclosed in Seagates patent! But we grand Seagate sole ownership to use Gold with Cu, Rh, Ru, ... or Mo in concentrations of 0.5-30% in HAMR NFT. How does this benefit us?
Of course Seagate can't stop WD to use same alloys as WD have similar patents to sue back, but they both can stifle smaller competitors. I don't think there will be any more competitors in HDD space, but same applies to other fields and their patents.
[1] http://www.google.com/patents/US8427925
[Disclosure, I didn't read full patent application, did cursory review and didn't find anything of value]
Zak - Wednesday, July 6, 2016 - link
I was wondering why HDs never broke the 7500rpm and 15000rpm barriers.DanNeely - Wednesday, July 6, 2016 - link
For consumer devices: noise. 10/15k HDDs are obnoxiously loud like an >40x CD or >16x DVD drive; except that they're spinning constantly not just for the few minutes it takes to read/write them. On the enterprise side, I'd guess implementation difficulty; probably due to vibrations was the limiting factor. If not mechanical strength of the platters themselves was probably the issue. Top end centrifuges can go to at least 70k RPM; but can be built much more heavily than a thin platter can.metayoshi - Wednesday, July 6, 2016 - link
Not just noise, but heat. In a constrained system like a laptop or desktop, the spindle and vibrations cause a ton of heat to be generated. Just look at WD's last consumer 10k drive, the 1 TB Velociraptor. It's a 2.5" drive that comes with its own heatsink for 3.5" bays. You definitely can't put that in a laptop, and it hits a market in the desktop space which has pretty much been taken over by SSDs.piasabird - Wednesday, July 6, 2016 - link
Still using hard drives. No reason to switch when hard drives are so cheap. When I watch TV on the Internet, It still works so no reason to change.pavag - Wednesday, July 6, 2016 - link
Kurzweil curse.Nobody accounts the relative speed of price reduction. SSD will get cheaper per gigabyte than SSD before 2020.
We will never see HDMR HDD. And there is a chance we will not even get HAMR.
And article speculating about the date when SSD will beat HDD for price per gigabyte would be interesting.
serendip - Friday, July 8, 2016 - link
I'm not sure about this. On my laptop, I've got a 120 GB SSD I got ages ago along with a recent 2 TB drive. Both cost about the same when new. I think HDDs will continue to get bigger and cheaper faster than SSDs, at least until some new process tech allows for very high flash densities and low production cost.The main issue is price. There are still lots of users (like me) who can't afford huge multi-TB SSDs to hold everything, so they have to make do with a boot SSD and a storage HDD.
jabber - Wednesday, July 6, 2016 - link
So you didn't bother to ask why Seagate's HDD reliability has nosedived since the floods a few years back?