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Hybrid Hard Drives Just Need 8GB of NAND
judgecorp writes "Research from Seagate suggests that hybrid hard drives in general use are virtually as good as solid state drives if they have just 8GB of solid state memory. The research found that normal office computers, not running data-centric applications, access just 9.58GB of unique data per day. 8GB is enough to store most of that, and results in a drive which is far cheaper than an all-Flash device. Seagate is confident enough to ease off on efforts to get data off hard drives quickly, and rely on cacheing instead. It will cease production of 7200 RPM laptop drives at the end of 2013, and just make models running at 5400 RPM."
No chance this is just the company saying this because they missed the boat on solid state drives?
The games I download from Steam are around 5GB each. So if I try playing two games in one day, only the first one will load quickly?
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... all solid state in my laptop. I hate hybrids.
now we need to go OSS in diesel cars
This looks like Seagate desperately clinging to their old bastion. Even Western Digital bit the bullet and started working on pure SSDs. The problem with Seagate's calculations is that there'll come a time (not that far into the future) where NAND will be cheap enough to get a full SSD for only a moderate price hike over a HDD, all while getting all the benefits of a pure SSD drive. They risk getting left behind by clinging to the hybrid drive idea.
SSHDs as implemented by Seagate do not require any support whatsoever in the host. Their caching algorithm does not care anything about the FS. It is block level. I have one working just fine in arch linux. Linux just sees it as any other HD, only it is much faster overall. Obviously you will never see any improvement at all in huge file copies.
WD has some lame Windows-only SSHD tech that does require special software on the host.
Yup, they missed the boat. Anyone who has used a SSD will go back to using a regular HD when they stop making SSDs, and the last available one breaks.
SSDs really are the bee's knees.
I am John Hurt.
I've used an SSD. Works great for my laptop and router, don't care for it for my desktop largely due to price. For $60, I can get an 80GB SSD or I can get a 2TB HDD. That 80GB SSD is going to require an additional HDD anyway for storage for many people.
Most consumers are still going to go with cheapest and, outside of the tech-oriented crowd, don't really care if they have to wait an extra few seconds. As far as I'm concerned, the SSD boat is still boarding passengers and is no where close to leaving just yet. Once SSD prices are more competitive with hard drives (which could be another decade or two at the least), then you can say that ship has sailed. Until then, cost will trump performance for the largest markets.
RAM cache is useless for speeding up writes. A significant (although workload-dependent) part of the performance problem with spinning disks is that if you issue a write and then need to block until it's on disk (which you need for consistency), it can easily take 5-10ms (or more) and that severely limits the performance. Often, non-server workloads include doing a lot of small synchronous writes and then no writes for a while. An SSD as a write-through cache works well here because it can reorder a lot of writes to turn (some of) them into sequential writes and it can trickle out a lot of writes while the disk is idle. This is also pretty much the best case for flash longevity: you don't need wear levelling, because you just treat the entire flash as a ring buffer and write to one end and write to the disk from the other end. You can keep the translation layer in RAM, and if there's a power failure you just replay the entire flash journal onto the disk.
The 'only reads 8GB' of unique data per day number is meaningless as an indication of how often each thing is used, however. If each day you always access the same 8GB, then an 8GB cache will be perfect for you. If you always access 8GB a day and you only access 7.5GB of it once, then a 512MB cache will be fine and you'll get no benefit from more, but you will get a big benefit from having a faster underlying storage device.
I am TheRaven on Soylent News
The lifespan issue with SSDs has three main factors.
1: Type of flash memory (SLC, MLC, TLC, in order of decreasing durability)
2: Size of the flash drive (larger drives have more room for wear leveling algorithms to work with, thus staving off flash cell burnouts due to exceeding maximum number of writes).
3: The amount of throughput on the flash drive. An expected heavy load is roughly 10GB/day. Doubling the load halves the lifetime of the drive. Quadrupling the load quarters it.
Granted, the cache on a Hybrid is being used a bit differently than how you would use a straight SSD. But, with such a small cache drive, you ARE going to wind up cooking it after a relatively brief period of time.
Chas - The one, the only.
THANK GOD!!!
They aren't claiming that 8GB flash makes the drive as good as SSDs. They are only claiming that it will be equivalent for most users.
If most users only use the computer to boot the OS and start the browser then I don't doubt that claim at all, but then they can just install the OS on an 8GB SSD (Or 30GB if you can't find anything smaller.) and skip the HDD part entirely.
I took into account cost, capacity and performance when choosing the drives.
But not battery life, apparently, which is the one area where 5400 rpm drives beat out 7200 rpm drives, and is possibly the reason they even exist. A 5400rpm hybrid would need to spin up even less and should do even better on the battery front. Not to mention that if you get a cache hit, it doesn't have to spin up at all, which is a big performance boost too.
So while "benchmark" performance might not be great, real world use might be substantial; as the hard drive could spin down more, and you could access the drive without spinning it up some of the time, possibly even most of the time.
There's definitely potential to be both markedly faster in real world laptop use scenarios and consume less battery with a hybrid. Whether that pans out in reality I don't know.