SSD Storage: 2018 in review

https://www.anandtech.com/show/13752/anandtech-year-in-review-2018-ssds

by PeterZaitsev • 8 years ago

173 126 8 years ago

Not sure if I'm asking this correctly but, all SSDs now have their own internal filesystem for managing access to blocks right? Are we getting to a point where traditional filesystems like NTFS or ext4 will simply go away? Or will they still stick around and just act as lightweight layers on top of the SSD filesystem?

iwalton3• 8 years ago

Those filesystems seem to handle different design requirements though. I also don't trust most vendors to properly encrypt the drives in the firmware [1], so I end up putting dm-crypt over most drives. It also doesn't account for raid setups, which are usually done at the block level. (Although I like snapraid for some use cases.)

[1] https://www.welivesecurity.com/2018/11/15/security-researche...

megous• 8 years ago

I think it's unlikely that manufacturers will want to turn their consumer SSD devices into a dumb flash storage and move their FTL into the open (like a API layer inside the Linux kernel). It's where their added value lies.

wmf• 8 years ago

I think we're talking about the opposite where the SSD could take over some functionality from the OS.

Dylan168072• 8 years ago

Probably not putting drives in charge of the entire filesystem, but object storage would be a good way to let the drive manage itself and take care of the details of where to store everything. The SCSI commands for object storage have existed for a decade but so far haven't seen much uptake.

Moral_• 8 years ago

Those flash translation layers on the SSDs are generally used to maintain QoS/and do wear leveling, block management etc.

I don't think we'll see file systems go away, but what we may see is more knowledge pushed into the file system, instead of keeping it down in the controller.

We have started to see that with the advent of LightNVM which exposes a more RAW API into the drive and the FTL is maintained in the kernel. The current "generic" implementation of the LightNVM FTL is called pblk:

https://elixir.bootlin.com/linux/latest/source/drivers/light...

wtallis9• 8 years ago

The flash translation layers in SSDs implement things equivalent to the journalling functionality in modern filesystems, but they don't really provide any hierarchical organization of data. So you'll still need a normal host-based filesystem for the foreseeable future, but filesystem design can be influenced by the assumption that it's running atop flash storage.

There are several efforts underway to provide more specialized software interfaces to SSDs. Several vendors have produced models that expose a key-value store instead of fixed-size block storage; with those drives, you can throw away RocksDB and speak directly to the drive with the same semantics (subject to limitations on supported key and value sizes).

There are a few competing standards for open-channel SSDs that move some of the FTL onto the host CPU so that the journalling overhead doesn't have to exist at multiple layers; the different solutions here vary in terms of how much complexity they move to the CPU vs. how much abstraction the SSD still provides for the sake of software portability. Most of the potential benefits this approach provides are being subsumed by extensions to the NVMe protocol that allow the host and SSD to exchange optional hints about data layouts, GC status, etc.

SK Hynix recently announced they're working on a SSD with transactional storage support, so that the host can send multiple write commands and either commit or abort the transaction as a whole.

kbuck• 8 years ago

At the SSD level, the drives are actually doing block management, not file management. You still need a filesystem to store metadata, manage the layout of the data, etc.

An example of something that a SSD's controller does that the operating system/filesystem doesn't have to worry about is managing bad blocks. If the SSD detects a bad block, it will replace it with a working block and update the data used by its flash translation layer to move the blocks around. This is completely opaque to the operating system; as far as it knows its underlying storage works exactly the same (until there are so many bad blocks that the drive can't keep up this convenient deception).

An example of something a filesystem does that the SSD doesn't provide is storing operating system-specific file metadata, such as permissions, creation times, multiple data streams, directory layouts, etc. SSDs deal only in blocks of data, not arbitrarily-sized units, nor metadata.

The reason that this behavior isn't more tightly-integrated is because some of the details of managing the underlying flash blocks tend to be specific to type of flash, or even different models of flash. For example, the article mentions QLC flash becoming mainstream - we're finally getting to this point because previously, QLC was so difficult to manage that your filesystem had to be aware that it was writing to QLC flash to use it effectively. There are a few filesystems designed for direct flash management like yaffs[0], but this isn't quite as efficient as a SSD's dedicated processor and software stack.

[0] https://yaffs.net/

amelius• 8 years ago

This is completely opaque to the operating system; as far as it knows its underlying storage works exactly the same (until there are so many bad blocks that the drive can't keep up this convenient deception).

Is there a way for the drive to tell the fs that a block is bad? Or does the drive simply keep a bunch of blocks apart just in case?

alxmdev• 8 years ago

Exciting times indeed, just type "ssd" in your favorite search box. I'm about to upgrade to a 512GB SSD that costs half what an SSD half its size used to cost 5 years ago! Starting this year, I'm considering getting a low-end 120GB for $25 every year on January 1st to use as a write-once backup for all my work.

sigstoat3• 8 years ago

edit: i cannot arithmetic today, or sanity check my arithmetic. sorry.

sigh.

fourthark• 8 years ago

do you trust a startup still to exist in 41 years, and to honor your plan that long?

coder543• 8 years ago

I'm not sure how you got that $25 = 41 years of 120GB of storage on Backblaze.

Their current pricing appears to be $0.005/GB-month... which would be $295.20 for 41 years of 120GB of storage.

i wouldn't trust a cheap SSD to still work in 41 years

I wouldn't trust almost any company to still exist in 41 years, including Backblaze. Preserving data over that length of time will probably require active management of the data in some form or another. DVD or Blu-ray discs might last that long... but it's hard to trust any storage medium to last for 41 years. Modern storage technology just hasn't existed that long.

megy• 8 years ago

that same $25 buys you 41 years of storage on backblaze

What. I just checked backblaze, it was $5 a month, or $50 a year.

DanielDent2• 8 years ago

As I understand, SSD would be an especially poor choice for this - an SSD left unpowered for an extended period will begin to experience data durability issues. The firmware of a powered SSD will mitigate this issue by engaging in periodic refresh activity.

This is a classic use case for tape. LTO drives support reading up to 2 generations earlier, i.e. an LTO-7 drive can read an LTO-6 tape. By not using the latest standard, you should be able to find cheaper drives, but the risk becomes always being able to find a (working) tape drive that is capable of reading your specific tape.

All of a sudden spinning rust drives start to look pretty good...

sunseb• 8 years ago

What about a Industrial SLC SD Card ? Like that:

https://swissbit.com/products/nand-flash-products/cards/sd-m...

Is it safe for backup or same problem?

karavelov• 8 years ago

Flash cells leak and degrade. Some firmwares also have bugs - not refreshing cells frequent enough even if the drive is powered. The leaks are even worse on high-write-endurance enterprise drives. Make sure you read the specs and don't expect to be able to read without errors a SSD that was offline for 1-2 years.

rb8082• 8 years ago

write-once backup for all my work.

I'd expect USB drives to be more durable. Would be nice to know.

camerondoll• 8 years ago

I wish Intel Optane nvme sticks had more capacity. The 120gb drive turned my i7 6500u laptop TWICE as fast as desktop AMD 1700x with regular drive. For example Python tests on a fairly big app ran for 3 minutes on a laptop and same tests about 7 minutes on a supposedly more powerful desktop machine.

Edit: by regular I mean 960 evo

wtallis9• 8 years ago

Two interesting updates based on what's been announced so far in 2019:

PCIe 4.0 will be arriving in the consumer market this year, with a new generation of AMD Ryzen CPUs providing host support, and at least one or two consumer-class NVMe SSD controllers supporting PCIe 4.0 should be ready to start shipping in retail products by the end of the year. (The enterprise/datacenter storage market's transition is already well underway.)

Seagate became the first vendor I'm aware of to start marketing a SSD to the prosumer/SMB market for NAS usage. It's a rebadge of one of their recent enterprise SATA drives and isn't even using QLC NAND so it's probably going to be pretty pricey, but the idea of a solid-state NAS is no longer completely laughable.

devereaux4• 8 years ago

solid state NAS not not laughable, just expansive.

RAID 10 a few NVME and you can get decent throughput (and storage size) with existing technology.

da_chicken• 8 years ago

I don't know that I'd consider RAID 10 for prosumer. RAID 1, absolutely. RAID 10 seems like needlessly adding more complexity and higher failure rates.

leetcrew• 8 years ago

RAID 10 a few NVME and you can get decent throughput (and storage size) with existing technology.

is there a good reason to do this in a consumer setup? max realistic throughput over gigabit ethernet is only ~120MB/s, which can easily be saturated by sequential reads or writes to/from a single modern spinning-rust drive.

walrus012• 8 years ago

I wouldn't RAID10 anything, but it's totally feasible to build a ZFS RAIDZ2 pool with hotspare out of a whole bunch of 2TB SATA3 SSDs. People do similar for 'budget' video editing setups.

imtringued2• 8 years ago

NVMe SSDs only significantly increase bandwidth, but not random throughput. Unless you have a 40gbit network you're not going to see the difference between one NVMe SSD or two if you're accessing them over the network.

eggsome• 8 years ago

Not _quite_ consumer, but we run a QNAP TES-3085U at work. Fully populated with 24 x 4tb EVO drives ends up being way faster and cheaper than our spindle based EMC. (although less reliability since it won't survive a cpu failure).

kingosticks2• 8 years ago

How does it work out cheaper? Is this DIY vs a product?

franciscop5• 8 years ago

I've been following the news and it's amazing how SSDs are still progressing, a bit slower but similar to Moore's Law. Prices for Samsung SSD 1TB external USB products:

- 2015 $600: Samsung T1 http://www.thessdreview.com/our-reviews/samsung-portable-ssd...

- 2016 $430: Samsung T3 https://www.storagereview.com/samsung_portable_ssd_t3_review

- 2018 $200: Samsung T5 https://www.androidheadlines.com/2018/12/samsung-t5-portable...

Another incredible exciting point is the amount of competition coming up, it's not just 2-3 large vendors anymore.

If things continue at this pace it seems sensible to expect a 10TB SSD consumer drive for under $1000 within a couple of years.

Note: not afiliated at all, just a happy consumer.

baroffoos2• 8 years ago

I await the day I can fill my NAS with SSDs. Might save on power usage as well.

elorant• 8 years ago

Not sure if it's a good idea though. SSDs tend to fail without warning. I guess that's why we have RAID but still I wouldn't want my backup storage to be so volatile.

glitchc• 8 years ago

SSDs consume more, not less power, to comparable spinning HDs, especially in always-on scenarios. Once started, the amount of power required to keep a platter spinning is miniscule.

gammateam3• 8 years ago

I had planned on doing this but even with gigabit wifi, and half gigabit transfer speeds for the SSD, NAS encryption algorithms seems to cap the transmission speeds to around 100 megabytes per second

I have all the parts I just haven't formatted my SSDs to go into the NAS yet and I'm not sure if I will

WaltPurvis2• 8 years ago

I'm surprised how quickly prices are falling.

I purchased a 500GB EVO 860 only 7 months ago for $139.99.

Just checked and it's currently $82.99.

For only $8 more than I paid for that 500GB SSD, I could now get a 1 TB SSD.

(Naturally, I've barely used that drive, which was slated for secondary storage, and now I wish I had waited.)

segfaultbuserr2• 8 years ago

In June 2015, I found the price of a 1 TB SSD was 400 USD, and in December, the price had fallen to 300 USD. In June 2017, I checked the price again and found it was 250 USD. I've put the numbers in my calculator to perform a curve-fitting using the exponential function, and it suggested that "I'll be able to purchase a 1 TB SSD for ~140 USD in 18 months", and I left the number a future note. Now, it turned out the regression analysis was almost correct (only for unnamed cheaper brands for now, I expect more reliable products are coming soon). The "Moore's Law" is really working.

disishhsha• 8 years ago

I wouldn’t worry about it. If you barely use it, what are the odds you’ll ever fill it up? And if you do fill it up, SSDs will be even cheaper then.

memco• 8 years ago

Meanwhile Apple is charging $1,200 for a 1 TB MacBook upgrade. Hoping this year we see a significant jump in consumer availability of these drives. I’ve been using a 512gb laptop since 2010 at least. Would be nice to start seeing multi-terrabyte drives in devices besides after market or external drives.

jjeaff• 8 years ago

What would consumer availability have to do with the $1000 apple tax?

1tb SSD are already significantly cheaper than what they are charging. They don't seem to base their pricing on cogs.

dylan6043• 8 years ago

To be fair, the $200 1TB SSD linked above is just a standard 2.5" SSD where the Apple SSDs are M.2 with triple the I/O speeds. These Apple(s) can't be compared to the list of oranges above.

SyneRyder• 8 years ago

Meanwhile Apple is charging $1,200 for a 1 TB MacBook upgrade.

This is specifically one of the reasons I ended up switching to a Lenovo Thinkpad X1 Yoga, even though I'd planned to buy the new MacBook Air. The Thinkpad's SSD is officially user-replaceable and I bought a 2TB WD Blue SSD for less than a third of the cost of Apple's upgrade. Even an NVMe SSD would have been half the price of Apple.

One caveat is that although Lenovo has excellent official repair videos (https://www.youtube.com/watch?v=PqrspYc21PY), I must be doing something wrong, the Phillips & JIS heads in my iFixit Mako toolkit don't seem to fit/grip the Thinkpad's SSD screw. I'm worried I'll strip the screw if I keep trying, so I guess I'll take it to a Lenovo repair shop for some help.

garyclarke27• 8 years ago

Agreed I’m still using my late 2013 MBPro with 1TB ssd 16gb Ram, because it feels to me that Apple prices for the 1TB ssd have not reduced at all, I want to upgrade and I can afford it, but I hate being ripped off, so I’m stubbornly waiting for a price drop. I like 1TB because I need to run Windows 10 and MacOS. Apple makes the most reliable windows pc according to some stats (a few years ago) I saw from Microsoft and I believe them, runs Bootcamp Win 10 Office 64 bit Excel v heavy workbooks better than any other machine I’ve tried

woolvalley2• 8 years ago

I wouldn't use external SSDs as the price benchmark, since they had a big price premium over an equivalent mSATA SSD back then.

For example, I bought a 1TB samsung mSATA SSD in 2015 for about $320 and it's enclosure for $15. The equivalent SSD today is about $150. So instead of a 3x price decrease in the past 3 years, it's more like a 2x price decrease.

bluedino• 8 years ago

mSATA SSD's are so rare these days

franciscop5• 8 years ago

I agree, there is more overhead. But since I'm interested mainly in external SSDs I'm tracking those :)

Please feel free to create a similar list with 2.5", mSATA or m.2 drives, it probably is even more shocking.

The other awesome thing about those 3 I linked is that the interface also has changed: Micro USB 3.0 => UBS-C Gen 1 => Thunderbolt.

nimbius• 8 years ago

surprised these are still a thing. I bit the bullet and moved to M.2 storage across pci lanes. It makes my current SSD's feel like spinning disk.

https://en.wikipedia.org/wiki/M.2

aidenn0• 8 years ago

TFA includes discussions of all SSDs, M.2 formfactor included.

reasonablemann• 8 years ago

Why is there competition in the SSD market but not in the RAM market?

wtallis9• 8 years ago

I'm not sure. The pattern in the DRAM market seems to have been that only the biggest, most successful manufacturers can weather price crashes while still investing enough in R&D to stay on the leading edge. In the NAND flash market, we may simply not have yet seen any oversupply serious enough to do that, for all that we're in the middle of an oversupply-driven price crash.

It is probably the case that it's easier to stay in business with inferior NAND; Samsung beat everyone else to 3D NAND by a few years but Toshiba still made a killing off cheaper, lower quality planar NAND, and Intel/Micron didn't seem to suffer meaningfully from their first-generation 3D NAND being so slow. Now everyone other than SK Hynix has caught up to Samsung and the number of players in the market is actually increasing.

ATsch• 8 years ago

The recent scandals about DDR4 price fixing lead me to believe it's probably collusion.

kingosticks2• 8 years ago

Could it also be partly due to the infancy of the technology and the market? You don't see new RAM vendors and there are fewer avenues of improvement left to explore. That leaves a race to the bottom which is pretty unexciting for everyone.

jaytaylor• 8 years ago

Whoa, check out that Samsung NF1 form-factor [0]. Looks like you could pack a ton of small finger-sized SSD drives vertically into a small space.

[0] https://images.anandtech.com/doci/13752/IMGP2727_575px.jpg

This is one way in which it's a cool time to be alive. I'll never forget circa 1996 when I waited 20+ minutes for my Apple Performa 550 to read and load a 30MB file from the scsi disk into memory. All so quicktime could play a grainy, low-resolution video clip for all of 30 seconds. At the time I was like "That's almost 1 minute per second of video! WTF? That sucks."

wtallis9• 8 years ago

That picture is actually the EDSFF 1U Short form factor, which is the closest competitor to Samsung's NF1 out of the variety of form factors defined by EDSFF. Both allow for about 36 drives in the front of a 1U system.

woolvalley2• 8 years ago

That must get really hot, I wonder how well it cools?

wtallis9• 8 years ago

There's no backplane to get in the way of airflow, so it is quite a bit easier to cool than a typical hot-swap bay full of 2.5" drives: https://images.anandtech.com/doci/13218/IMGP2722.jpg

The new connectors between the drives and the mid-plane board are probably the most important innovation these new form factors bring to the table, though something similar could also be done for existing SAS/U.2 connectors.

manmal• 8 years ago

Don't they just use 1W each, making up 16W in total? I might be dead wrong. But 16W should be easily transported off by the metallic case and a smallish fan?

walrus012• 8 years ago

How many M.2 2280 format NVME SSD can you fit in one of those modules?

rb8082• 8 years ago

The other amazing thing is size. How much smaller and cooler m2 drives are compared to old 3.5" HDs. If you have integrated graphics, PCs can now be tiny. The big tower cases are really for gamers only.

zanny• 8 years ago

Even gamers don't need towers, games don't benefit much from anything > 4 cores and the only limiting factor so all you really need is a mini-itx motherboard, 8-16GB of ram, and a beefy GPU attached. There are plenty of console sized cases out there you can build in that can fit a 2080 or Vega card.

Big cases are really for tons of mechanical drive capacity, > 8 core CPUs, addin cards like network switches, or a ton of GPUs in a compute cluster.

kevin335200• 8 years ago

Just bought MX500 2TB in black friday for about 200 euros. Maybe it will getting cheaper this year, but 0.1 EUR/GB is already a good deal for me

SSD Storage: 2018 in review

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