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Seagate's New SSHD Hybrids Have Dual-Mode Flash Caches
crookedvulture writes "Seagate's has revealed its next-generation hybrid drives, and for the first time, there's a 3.5" desktop model in the mix. The new family of so-called SSHDs includes standard and slim notebook variants with 500GB and 1TB capacities, plus 1TB and 2TB desktop versions. All of them combine mechanical platters with 8GB of NAND in a dual-mode SLC/MLC configuration. The SLC component is largely reserved to cache host writes, while the MLC portion is filled with frequently accessed data to speed read performance. Despite MLC NAND's lower write endurance, Seagate claims the SSHDs have more than enough headroom to last at least five years with typical client workloads. More impressively, the mobile SSHDs are supposed to be faster than the old Momentus XT hybrid even though they have slower 5,400-RPM spindle speeds. The mobile models are slated to start selling shortly at $79 for 500GB and $99 for 1TB, while the 1TB and 2TB desktop flavors are due in late April for $99 and $149, respectively. Unlike other NAND caching solutions, Seagate's tech requires no software or drivers, making it compatible with any OS."
Why is this better than having 1/2 boot SSDs and an HDD RAID for storage?
Ah crap! I just bought the Momentus XT 750 version a couple weeks ago. I'm pleased with it. Not as fast as SS drive, but roomier and cheaper. But crap, if I'd just waited ...
Then again, I was expecting the next version to have 16 or 32 gig of flash. And I did get a 7200 rpm drive. Handy for some of the huge files I process.
The world is made by those who show up for the job.
Seagate claims the SSHDs have more than enough headroom to last at least five years with typical client workloads.
The typical client workload is that user powers on own computer, windows starts and then user opens WWW browser and browse web and then does some files with MS Office and turns off the computer.
How about those typical client workloads where almost every day is needed to manage 16-30 gigabytes of new data, what gets edited and copied multiple times?
it wouldn't be too bad if the ssd side was like 80 gigs.
but it's not. it just couple of dollars worth of chips now and seagate acting as if it was something else.
world was created 5 seconds before this post as it is.
Considering Newegg has 3 TB for $140 on sales, and these look like they cost about 2x too much, AND given my personal experiences with Seagate 500 gb drives of all kinds. No thanks. I think I'll wait for the 1 TB flash drives Kingston supposedly demoed at CES already instead.
For a mere 8GB acting as cache in the drive, I'd rather spend $30 on RAM and let the OS use it for buffering/caching data (which Linux at least will do pretty intelligently for me even without changing /proc/sys/kernel/whatever).
I love my SSD but that's way more than 8GB. As an extra bonus, the RAM can be allocated as necessary, is faster, and there are no write/erase issues with it.
Now, come up with say 2TB on platters and 128GB flash and we're talking a different proposition.
8GB might be sufficient for those who care about how quickly they boot up (assuming the bulk of the kernel etc ends up in the flash cache and stays there until shutdown) but I only reboot about once a month at most.
The cache on your CPU is "stupid-caching" everything too, making it compatible with different OSes. Think about that. You're stupider than you think.
*facepalm* One of the major design decisions in CPU architecture is cache optimization. Over half of the silicon in your CPU chip is cache. Saying that CPU caching strategies are as optimized as the drive referenced above is so stupid that God probably had to kill a kitten.
#fuckbeta #iamslashdot #dicemustdie
Spoken like someone who hasn't actually used a latest gen SSD yet. I used to be on your bandwagon, thinking my striped raid was good enough.
There is just no getting around the fact that essentially zero seek times and 400MB+ reads and writes are just so much better than platters can manage.
I will never build another computer without at least a small SSD for the OS and related software.
If sharing a song makes you a pirate, what do I have to share to be a ninja?
Given the relative ease of failure for flash memory compared to mechanical, the Momentus XT 7200's will end up winning on the long term.
Twitter supports and protects racists - by smearing their critics with the "Hate Speech" label.
8GB might be sufficient for those who care about how quickly they boot up (assuming the bulk of the kernel etc ends up in the flash cache and stays there until shutdown) but I only reboot about once a month at most.
you can buy a USB 3.0 stick and put your OS on it if you care about it that much. 8GB is nothing. Without any drivers so the OS can be aware, it's basically an HDD with one duct taped to it anyway...
#fuckbeta #iamslashdot #dicemustdie
Flash makes little difference to read performance, but can make a huge different to write speeds. RAM, being non-volatile, means that if an application calls fsync, you block until all of the data has been flushed to the disk. With a flash write cache, you can buffer a load of writes and return almost immediately (writes into flash can easily go at 100+MB/s) and then write them out to disk when it is idle or less loaded.
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Will these drives finally break the 5.9 barrier? From what I've heard, the old XT's didn't.
I have the first gen XT and I can say is that these things are everything they're cracked up to be. If you're not buying an SSD then you should be getting one of these. Generally if you strip away the SSD portion you're still left with one of the best mechanical drives on the market, but the SSD portion really and truly does make a solid and positive difference in everyday computing life.
I'll agree that this may not be the drive we're looking for, but to expect that SSDs don't offer much benefit day to day because of RAM caching is false. Yes, initial startup is faster (in my case *minutes* faster), but even loading and unloading frequently used applications is markedly better. The performance increase on startup and access of local files was an order of magnitude - every time I switch applications or projects - and I have 24GB of RAM.
Speeding up access to my on-disc document library, or my current 20+/- project folders, would actually be a help if I couldn't afford a SSD. Still, 8GB is pretty paltry imho.
Is it just my observation, or are there way too many stupid people in the world?
"Once your RAM file cache is more than the files you load, file access is essential zero seek and 2GB+ reads and writes. Don't forget here we're talking about RAM. The disk is NEVER touched once its cached, there's no possibility for a disk that isn't being accessed to speed up a read from the RAM cache, and no benefit from speeding up a deferred write that's done in the background."
You don't know how writes in a filesystem work. It isn't just the data that gets written and not every write can be deferred.
If your "disk light never blinks" you aren't using your computer.
Disk storage contains filesystem metadata. Sooner or later writes *have* to go to disk regardless of how much RAM you have. Flash can accelerate that. RAM and flash are not interchangeable and 8GB can be enough for some applications.
Block level SSD can cache filesystem metadata that the "OS' own cache optimization routines" cannot.
It helps to actually understand what you are criticizing in such a juvenile manner. Catch up.
All caching is stupid caching until its behavior appears smart. Block caches are as capable of that as any.
Memory caches are useless because they are hung on the side, can't be independently accessed, and basically stupid-cache everything. Right, systems-architect?
I really wish that drives could be optionally set (via a jumper?) to allow the OS to see these built-in SSDs, and not have them hidden behind the firmware.
There are more and more systems out there can configured to intelligently use flash: Linux has Bcache; FreeBSD, Solaris, and Mac OS X have ZFS. I'd love to be able to set up a home server to use these drivers for read (L2ARC) and write (ZIL) acceleration, and I'm sure a lot of OEMs would love to have distributed/striped flash in their storage offerings.
The bulk volume of spinning rust, and the IOps of flash, all in one convenient package.
If anyone at Seagate (or any other hard drive vendor) is listening: if you do this you will gain an immediate advantage over your competitors. (Until they copy you of course.)
Besides the write performance Raven noted, the flash block cache has two additional advantages over more RAM: depending on your workload, it's entirely possible for a working set to take up most of the 16GB limit for many systems these days, and all the RAM in the world doesn't help you on system startup. I have the second-gen XT, and there's a noticeable difference in boot/launch times the second and third time a version is loaded over the first.
Seagate Momentus XT 750GB in 2.5 inch form factor - perfect for an older laptop with a dedicated graphics card intended for both early generation games, temporary torrent storage and speed.
But pay attention to the price.
Flash is roughly $1/GB. 8GB of flash costs about $8, which is in line with the ~$10 price increase of an SSHD over a similar pure hard drive. At 128GB, though, you're spending as much or more on just the flash than the SSHDs here cost.
Not to mention the physical size. 128GB SSDs take up quite a bit of the space available in a 2.5" disk. You aren't likely to see a 2TB hard drive and a 128GB SSD in a single enclosure anytime soon, simply because that won't fit into a single drive bay.
Nobody ever said these weren't fast or cheap. What they did say was massive data corruption, nonstop blue screening, and completely inconsistent performance. Also, if the drives lose power, you're screwed even if it was idle because it wasn't idle. It was moving data between the cache and main storage based on usage counts. Those constant writes, by the way, kill the flash memory very quickly. Plus, you can have a mechanical failure. Forget any kind of data recovery too. These are a terrible idea. RAID arrays of SSDs for large storage of a 120GB boot drive with a 1TB secondary are both very cost effective solutions and are both much safer. 4x60GB Intel 330 drives in raid5 take up like 15 watts, cost under $300, and run at around 1GB/s read speed in real world tests. Even RAID0 2x60GB ones I've tested at 800MB/s read. 3x120GB drives in RAID5 is sometimes even cheaper and almost as fast.
why not have a 2-4GB ram disk with slower / older ram on some kind of card / sata device? Just use it for temp stuff and it does not need a battery back up.
>Yes I do, I compile large programs,
Lets make a bet, we'll take the same computer spec wise, mine with an SSD and yours with a regular HDD and we'll compile a large program; gcc or the entire FreeBSD ports. And you can pay me a dollar for every minute longer yours takes.
> and edit video.
Video editing is a different ball game though. You don't do much random IO, its mostly a streaming workload with very few head repositions. This is something that regular hard drives are good at.
Because it's faster and cheaper to just chuck more RAM in the machine. And you get about the same effect by using a USB stick for readyboost on windows or swap+logs on Linux.
>Granted they're faster than most peoples 5400rpm drive running in their laptops,
Not just faster, way faster. I've upgraded a number of clients computers from the crap HP comes with by default to XTs with the 8GB cache. Unless they have a very large working set of data they commonly use, the user will not notice a significant difference between the SSHD and an SSD.
If you tell most consumers do you want a 500GB SSD for around $500 or a 500GB SSHD for $79 where the $79 drive makes most, but not all things faster, most people will go with the second option, and most people will have made the right choice going with the second option.
There is only your cheapness. Drives are the slowest part of your gear. Scrimping a few dollars to make them sort of faster is more expensive than spending all the money you need to make them as fast and as reliable as possible.
Including building entire distros from source for embedded stuff. In my experience when compiling stuff the bottleneck is the CPU, not the disk. On the other hand, when trying to dig around in hundreds of megs of git repository it's a pain to wait for a spinning disk.
USB is slower with high CPU overhead and that eats up USB bandwidth that you may need for other USB stuff.
Flash makes little difference to read performance
I totally got my system configured wrong then, because I get ~1,000MB/s reads off my flash with 0.1ms access time (RAID-0), and ~110-160MB/s reads off my HDDs with 9ms access time. Please tell me how to reconfigure my system so that I can get the same performance from my HDDs as I do my SSDs. And before you ask, I also have a hardware RAID of 8 3TB drives, and it still isn't as fast as reading my SSDs.
I have never seen a situation where using a USB device was 'faster' than ANYTHING on a hard drive.
ReadyBoost has never made a USB 2.0 device faster than just pulling the original data off the hard drive.
Its a cute idea, but in practice it fails instantly.
Swap ... on USB? Are you fucking kidding? Do you have any idea how much that would suck absolute ass?
Your hard drive is orders of magnitude faster than your shitty USB device. My iron-oxide disk is at least 10 times faster than the USB3 key plugged into my machine, and thats ignoring my SSD boot drive speeds, which guess what they due to the speed graph?
USB* is slow, even at USB3 speeds its a dumb idea.
Persistent Volume manager for Kubernetes - https://github.com/dwimsey/openshift-pvmanager
why not have a 2-4GB ram disk with slower / older ram on some kind of card / sata device? Just use it for temp stuff and it does not need a battery back up.
I remember having an ISA card that acted like a RAM disk back when computers had much more serious memory constraints, I think I had it on an 8086, which had a 1MB addressable space limit.
It was incredibly fast, I was using it to hold temporary files to help speed up a sort that wouldn't fit in memory - I think it had 128KB of RAM and it was incredibly fast - well, as fast as an 8 - 16MB/sec ISA bus could be.
But I can't imagine that there's much of a market for this type of accelerator these days since most people that want fast RAM disk performance just add more RAM to their computer and let the operating system manage it - getting a new motherboard with more RAM capacity if needed. I did find this card, which includes a backup battery so it's not just a RAM disk, the contents don't go away when you turn off your computer:
http://www.newegg.com/Product/Product.aspx?Item=N82E16815168001
It probably has lower latency than an SSD, but it acts as a 1.5 Gbit SATA interface, so transfer rate is limited to 150MB/sec.
I've also seen SSDs on a PCIe card, but that's not quite the same.
That depends on what you're reading. It makes a huge difference if it's not one large file read sequentially.
Oh, I see you've compiled a large project at some point.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
8GB isn't enough cache for those of us who want the OS and multiple large applications on the SSD. But 32GB or 64GB of cache might be. I frequently use Xcode, Eclipse, Photoshop, Logic, and another dozen applications on a daily or weekly basis, and if I don't want to wait 30 seconds for Photoshop to start, then I'm still looking at getting a main 128GB SSD and a regular HD and setting up a Fusion drive, or just going all SSD. I somehow doubt 8GB of cache will live up to any expectations I have about loading times compared to the SSD that I'm used to.
Think of things like metadata. Even if you don't modify the file, things like "last access timestamp" is still altered, and need to be saved in persistent memory. So your HDD drive will blink at least a little.
Hi, welcome to Slashdot. For future reference, you may be aware of this little thing called 'context'. This means that words written in one post relate to things mentioned in the post that it is a response to. For example, my post was in reply to a post suggesting using more RAM, instead of flash. The context of my comment was that flash [as a cache] won't make a difference to read performance [relative to a disk behind a large RAM cache]. Interpreting it as saying 'an SSD is no faster for reading than a spinning disk' makes you look like you've just failed the Turing Test.
I am TheRaven on Soylent News
An off the shelf SSD I bought a year ago is still giving me read and write times far in excess of what I get out of an IBM 8Ki RAID card with an array of 15K RPM drives (RAID 5). No need for the latest gen SSD to prove that.
Calling someone a "hater" only means you can not rationally rebut their argument.
For future reference, being able to write so that you get your meaning across is apparently a skill that you lack. What you wrote could have been interpreted many ways, of which I read to mean one way, while you meant it another. Regardless of the context, and since this is a discussion board, you could have been trying to convey any of a multitudes of thought. I suggest you write your thoughts clearer in the future.
Indeed. This is precisely why high-end storage arrays have such atrocious performance.
Hi, welcome to Slashdot. For future reference, you are coming across as snarky and a bit of a dick. Which wouldn't be too bad if you had expressed yourself well... but you did not. I had to re-read your post, its parent, and your clarifying reply before I figured out what you meant. While I may be slightly tired from digging through EMC docs today, I would like to think my brain is still largely functional.
SWM seeks new sig for a brief fling