New Seagate Hybrid Drives Hampered By Slow Mechanical Guts 130
crookedvulture writes "Seagate announced its third-generation hybrid drives last month, revealing a full family of notebook and desktop drives that combine mechanical platters with solid-state storage. These so-called SSHDs are Seagate's first to be capable of caching write requests in addition to reads, and the mobile variants are already selling online. Unfortunately, a closer look at the Laptop Thin SSHD reveals some problems with Seagate's new design. While the integrated flash cache reduces OS and application load times by 30-45%, overall performance appears to be held back by its 5,400-RPM mechanical component. Seagate's last-gen Momentus XT hybrid spins its platters at 7,200-RPM, and it's faster than the new SSHD in a wide range of tests. The upcoming desktop SSHDs will also have 7,200-RPM spindle speeds, so they may prove more appealing than the mobile models."
semi serious question (Score:3, Interesting)
I would think it would be a better compromise, am I missing something?
Re:semi serious question (Score:5, Interesting)
Why are we not seeing more 10K drives? Other than the WD Raptors, I haven't seen 10K desktop drives in forever.
I would think it would be a better compromise, am I missing something?
10Ks on the desktop(and, at least to some degree, although less of one, 10 and 15Ks in the enterprise) have been curb-stomped by SSDs, actually harder than their slower brethren.
Everybody knows that 5.4s and 7.2s are horribly slow, for everything except very well behaved linear reads or writes; but they are insanely capacious and cheap, so people who don't need speed buy them anyway, and by the truckload. On the consumer end, cheap shit sells by the pallet, and needs something to boot from, and on the enterprise side the (partial) unification of SAS and SATA means that a lot of stuff that you used to have to dump right to tape can now be handed off to crazy-cheap 'nearline' HDD storage(and, in sufficient quantity, a lot of less demanding storage tasks are perfectly fine on prosaic 7.2K SATA, and since SATA drives drop right into SAS slots/connectors, they all play nicely with the RAID backplanes and hot-swap trays and things, which wasn't the case back in the PATA/SCSI days).
Among people who need I/O above all, any mechanical drive is an amusing little smudge clinging to the X axis when graphed against the performance of any halfway decent SSD. When a good SSD can easily be several orders of magnitude faster, the fact that you might(best case) triple performance by going from 5.4k to 15k barely registers; but the price of increasing spindle speeds certainly does.
Velociraptors, and their ilk, had a brief period of popularity back when all the 15Ks were SCSI(and so were either wildly expensive, or dodgy fleabay gear, and usually needed an add-on card that cost more than most consumer hard drives, even used) and SSDs were either nonexistent or more expensive than entire workstations. Now, they just aren't a terribly impressive offering. If you don't care much, you can get a rather larger and quieter HDD for substantially less money. If you do care, a surprisingly small premium will get you an SSD that will blow the Velociraptor out of the water.
The gulf between good solid state storage and mechanical storage, in terms of latency, is just so enormous that we will probably see more retreating from higher spindle speeds than advancing. High precision, high reliability mechanical parts are stubbornly costly, so increasing spindle speeds isn't free; but the performance gap is sufficiently vast that even some terrifying HDD built with ultracentrifuge technology just isn't going to be as fast as an SSD. Flash prices are still high enough that HDDs have plenty of retreating room into high capacity/high latency applications; but any attempt to achieve parity in low-latency work would just be comedic(if probably impressive from an engineering standpoint, and when it tore itself apart and shredded everything nearby)...
Re:Epic failure (Score:5, Interesting)
I would strongly suspect that it's an OEM thing, mostly:
Intel, for one, sets some fairly strict boot-time requirement for an OEM to be able to slap "Ultrabook!!!!" on the laptop and possibly get some Intel 'marketing assistance' cash. Microsoft has also been doing a bit of leaning on OEMs in terms of how fast Win8 machines need to boot in order to earn their little sticker of meaningless approval.
OEMs, of course, still need to shove $400 black-friday specials out the door. What will we do? Well, it just so happens that our good buddies at Seagate have a hard drive that is super cheap, being a very undemanding mechanical model with only a small amount of flash; but just so happens to be able to(if configured and pre-cached and whatnot properly) boot the OS like a bat out of hell... Seagate proceeds to sell a giant pile of the things.
Given that Seagate knows that benchmarks are going to happen, they have no realistic hope of pulling the wool over the eyes of informed enthusiasts. I'd be surprised if they care: less cost-sensitive enthusiasts are going to buy SSDs anyway, more cost-sensitive ones may well buy if the price is right, and making the spindle slow and the cache small will definitely help there.
As a strategy for launching a successful enthusiast storage brand, Seagate's choices would be suicide; but 'enthusiast storage' isn't a terribly big market anyway, and the SSD guys own it now, so Seagate doesn't have a choice about not playing there. The OEMs, on the other hand, are caught between certification demands(which generally specify boot time, resume-time, etc. not 'IOPS Random 4k' scores) and price pressures. This product looks like it is tailor-made to be pitched right at them.
Re:Hey, Seagate: (Score:5, Interesting)
Certainly, technology producers change their designs as they go, making them cheaper and cheaper until they just barely stay within the lower end of their specs. It's called "optimization", and it's the responsible thing for a manufacturer to do for its shareholders. Same volume, same price, higher return on investment. If you don't personally like it, you can pay more for a device with better lower-end specs from someone else.
In the case of hard drives, Seagate knows that 5,400 RPM machines are far more reliable than 7,200 RPM machines, even after optimization of both. I suspect that in order to make 7,200 RPM drives more durable, the manufacturing costs exceeded that of SSDs. And if 7,200 RPM drives can't be made more reliable for an affordable price, I expect that is why Seagate is dropping them completely.
Hybrids are a way to sell a slightly faster version of the mechanical drive for people on a budget who still need reliability. No, it's not going to out-perform a 7,200 RPM drive, but over time it will do better than a 5,400 RPM drive without a cache. If you want performance, spend the extra money for a real SSD. If you want cheap speed without reliability, you'll have to buy a faster drive from someone else.
Re:Hey, Seagate: (Score:4, Interesting)
and then praying they don't look an aisle over and realize that a modest SSD would blow it out of the water for not much more cash.
Only if they don't need the storage capacity of the spinning hard drive... many laptops don't have the room for both an SSD and a hard drive.
The smallest Seagate SSHD is 500GB and costrs around $99. The cheapest 500GB SSD I can find costs around $350.
So, for those that need the higher capacity, you can't get an SSD for "not much more cash".
So yes, an SSD would have much better performance, but not equivalent capacity at the same price point. For the kinds of things most people use a laptop for (booting windows, loading apps) the SSHD gives close to SSD performance, while still letting them keep their large media files on the hard drive
It's a douche move, but... it's sound business practice. Sell your customers down a river to keep profits up until you can turn up production on the Next Big Thing, and then try to buy them back later with discounts and deals.
Slower speeds aren't just a cost cutting move - cutting the speed reduces noise, power consumption (so you get better battery life on your laptop) and lowers heat production (so you get better reliability for your hard drive).
Re:Hey, Seagate: (Score:5, Interesting)
Their hybrid nature does not affect data recovery. All the onboard SSD does is cache data that exists on the HDD.
There is no way to know what will happen to the overall usability of the drive if the flash fails (either through normal write exhaustion or catastrophic failure).
Hopefully, Seagate did the right thing in this case and the drive would turn into the equivalent of a pure mechanical drive. But, failure of the flash or its controller might cause the drive to become completely unusable. Unless they specifically deal with this as a "special" failure mode, it wouldn't be that different from some essential part of the controller on a purely mechanical drive failing (like the DRAM cache), and that usually turns the drive into a doorstop.
Re:Hey, Seagate: (Score:4, Interesting)
And why are the magical unicorns going extinct? No demand. People on a budget buy a slow drive, people who can afford slightly more buy an SSD hybrid, people who have the means and require the performance buy an expensive SSD. If Seagate saw there was a market for expensive yet still slow 7,200 RPM drives, they'd keep making them. (Actually they still do have a few, it's their corporate customers who are too large and slow to make a more rational decision.)
Sorry I wasn't clear about the reliability thing. Seagate's 5,200 RPM drives have twice the reliability when compared to their 7,200 RPM drives (the Annual Failure Rate is predicted at 0.48%[1] vs 1.065%[2]), and the difference made by adding the complexity of a cache gives them a predicted AFR of only 0.50%. And reliability is absolutely driving this: if they have to double the reliability of their 7,200 RPM drives, they will cost more than plain old SSDs (also at 0.50% AFR[1]).
[1] http://origin-www.seagate.com/internal-hard-drives/laptop-hard-drives/ [seagate.com]
[2] http://origin-www.seagate.com/internal-hard-drives/enterprise-hard-drives/hdd/enterprise-value-hdd/ [seagate.com]