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Samsung SSD 840 EVO 250GB & 1TB TLC NAND Drives Tested
MojoKid writes "Samsung has been aggressively bolstering its solid state drive line-up for the last couple of years. While some of Samsung's earlier drives may not have particularly stood-out versus the competition at the time, the company's more recent 830 series and 840 series of solid state drives have been solid, both in terms of value and overall performance. Samsung's latest consumer-class solid state drives is the just-announced 840 EVO series of products. As the name suggests, the SSD 840 EVO series of drives is an evolution of the Samsung 840 series. These drives use the latest TLC NAND Flash to come out of Samsung's fab, along with an updated controller, and also feature some interesting software called RAPID (Real-time Accelerated Processing of IO Data) that can significantly impact performance. Samsung's new SSD 840 EVO series SSDs performed well throughout a battery of benchmarks, whether using synthetic benchmarks, trace-based tests, or highly-compressible or incompressible data. At around $.76 to $.65 per GB, they're competitively priced, relatively speaking, as well."
How many effective READ/WRITE cycle can the chip in SSD perform, before they start degrading ?
Has there been any comparison made in between the reliability (eg read/write cycles) of old fashion spinning-plate HD versus that of SSD ?
Muchas Gracias, Señor Edward Snowden !
Note: Anyone here about any programs like spinrite or other for drive recovery for SSD's?
There is no such a thing except for the few that are just trying to dupe you into giving them money. Why? Well, as long as the drive's controller itself is working and the drive's internal state isn't corrupted you can read the cells indefinitely. You cannot write to cells indefinitely, but all major manufacturers these days promise that even if all the cells failed in the whole drive you should be able to read them. On the other hand, if the drive's controller goes bonkers or the internal state gets messed up there is *no software whatsoever* that can fix it. You'd have to open the drive and work with the actual flash-chips themselves in the hopes of recovering your data, and due to the nature of SSDs where the cells can be re-located at any given time for wear-levelling purposes that'd be one helluva task.
Now, if your filesystems or such get messed up any tool that works on mechanical HDDs works just fine on SSDs. There is no difference.
I bought a samsung 840 128 gig drive( not pro ) and Iove it.
Yeah, we all like the look of the "hot" axis on the graph.
We're worried about the "crazy" axis. Most of us have a long term relationship with our data.
(for those who don't know: http://www.codinghorror.com/blog/2011/05/the-hot-crazy-solid-state-drive-scale.html )
nb. I've been using a 40Gb Intel SSD as my boot drive for a couple of years, it's still going strong AFAICT but there's not too many writes to that drive (swapfile and $home is on a velociraptor).
No sig today...
Except if you actually bothered to educate yourself, you'd find that at the capacities samsung is offering you, if you write to them at 10GB a day, every day, they'll last entirely respectable times (12,23,47,94 years respectively for 120,240,480 and 960GB drives).
The argument went on for about half an hour in EE lab, before the teacher came along and announced: "Yes."
Get thee glass eyes, and, like a scurvy politician, seem to see things thou dost not.--King Lear
You're talking about testing a device that doesn't even saturate 3 PCIe lanes, and complaining the test bed "only" has 16? Really?
One assumes this is windows software. Did the competing drives have their drivers installed too? I would want to see its performance without drivers installed and used as a plain SATA drive. And I would like to see with and without RAPID numbers.
Is RAPID a sophisticated buffer cache that is doing lazy writes to the SSD?
In the 2-5 TB range?
I previously would have maybe wanted this but not been willing to spend the money or expose my storage to disk failure with consumer SSD.
I'm thinking now it's getting to the point where it might be reasonable. I usually do RAID-10 for the performance (rebuild speed on RAID-5 with 2TB disks scares me) with the penalty of storage efficiency.
With 512GB SSD sort of affordable, I can switch to RAID-5 for the improved storage efficiency and still get an improvement in performance.
>all major manufacturers these days promise that even if all the cells failed in the whole drive you should be able to read them
and you should take such promises as having the same integrity as all other marketing claims - i.e they're probably not blatant lies.
A Samsung 840 endurance test posted in a comment above: They ran for ~3000 erase cycles until encountering the first unrecoverable read error at which point they declared the drive "dead" - it still seemed to work, but data had already been lost and more losses were inevitable.
http://uk.hardware.info/reviews/4178/10/hardwareinfo-tests-lifespan-of-samsung-ssd-840-250gb-tlc-ssd-updated-with-final-conclusion-final-update-20-6-2013
There's also unpowered data retention to consider - you're storing your data as a partial charge in a capacitor - 1 bit/cap (2 levels) for SLC, 2bits (4 levels) for MLC, or 3bits (8 levels) for TLC. And every one of those capacitors starts losing charge the instant it's written to - it does so very slowly, and typically starts out lasting for years (IIRC), but as the caps start wearing out and the charge levels get "fuzzier" that number can eventually drop to days, though supposedly that's typically well past the drive's rated erase cycles (i.e. folks hammering it 24-7 and hitting 30,000x erase cycles)
But yeah, you're absolutely correct that data recovery tools aren't going to be much use for an SSD where data is stored in discrete "bins", and either it's there or it isn't. Unlike a HDD where data is stored as magnetic "footprints" on a continuous media where even intentionally erasing it will tend to leave a portion of the print behind in the gap between tracks, which can then generally be recovered through repeated head repositioning and statistical analysis.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Usually, once you have your computer set up with your programs, you don't write a ton of data. A few MB per day or so. Samsung drives come with a little utility so you can monitor it.
As a sample data point I reinstalled my system back at the end of March. I keep my OS, apps, games, and user data all on an SSD. I have an HDD just for media and the like (it is a 512GB drive). I play a lot of games and install them pretty freely. In that time, I've written 1.54TB to my drive. So around 11GB per day averaged out, though realistically about 500GB of that was done the first day, since I installed the system, put the apps on, then changed my mind with regards to UEFI boot, and reinstalled the system.
I think some people believe that since they have a lot of data, they must write a lot and thus the write limit would be problematic. However the data you have is usually largely static. Your delta is fairly small and thus not that problematic to flash.
So while I wouldn't want to use TLC flash drives in a backup system or something, there really isn't an issue in a desktop. If you do have an atypical situation where you have very write intensive workloads, well you can always have a magnetic (or SLC flash) secondary disk for them. But for desktop usage, you just aren't going to write that much to your disk.
Here's the thing. SSDs are now more reliable than when this guy logged this report.
But are still maybe not as steady Eddie as a good-quality HDD. But we still want them because having an SSD boot drive changes the whole computing experience due to their awesome speed. And since we are good about backups (Are we not?) we can be relaxed as we ride the SSD smokin' fast Roller Coaster. SSD or HDD then what's the problem if we have data security. Both are gonna FAIL. So what if Miss SSD stabs me for no good reason? It was a helluva ride, Bro. And well worth the stitches. I do wish SLC NAND was not priced out of reach, but, hey, when it comes to hottness we take what we can get. Right?
Okay. This is Slashdot we get no hottiness...no hottiness at all.. No no no hottiness. It's pathetic really. ....
"No fear. No envy. No meanness." Liam Clancy
You'd need a better network to have any use. A modern 7200rpm drive is usually around the speed of a 1gbit link, sometimes faster, sometimes slower depending on the workload. Get a RAID going and you can generally out-do the bandwidth nearly all the time.
SSDs are WAY faster. They can slam a 6gbit SATA/SAS link, and can do so with nearly any workload. So you RAID them and you are talking even more bandwidth. You'd need a 10gig network to be able to see the performance benefits from them. Not that you can't have that in your house, but you don't because it is damn expensive. Lacking that, you'll notice very little improvement over magnetic drives.
Also to be technically correct (the best kind of correct) you probably don't have a SAN in your home. A SAN is a separate network, purely for storage devices, not connected to your LAN. It is a FC/FCoE/iSCSI/whatever backend that your storage devices talk on, and then there's a different network that your clients use to talk to the storage server (which is on both networks).
Most UPSes these days are line-interactive. That means they are not doing any conversion during normal operation. The line power is directly hooked to the output. They just watch the line level. If the power drops below their threshold, they then activate their inverter and start providing power. So while their electronics do use a bit being on, it is very little. The cost isn't in operation, it is in purchasing the device and in replacing the batteries.
That aside SSDs don't have problems with it (it was a firmware bug, Samsung fixed it) and if your data is important, you probably don't want to rely on your journal to make sure it is intact. When you get in to real high end, reliable, storage, power backup is a big thing. Our Equallogic has dual full redundant power supplies on all units, which they wanted plugged in to separate circuits (one is line only, one is generator backed), redundant controllers, and the NAS has internal batteries backing the cache in case of power failure, ones that last quite awhile.
There's a big difference between "a journal that means the filesystem isn't in an inconsistent state (usually)" and "a setup where one doesn't lose any data."
If you are concerned about efficiency costing you money in your computers (it likely costs less than you think) then your PSU is the place to look. If you didn't specifically buy a good one, it is probably 80% or less efficient. You can get them a bit above 90% if you try, and match them to the load.
I don't buy it when you discount a large number of anecdotal experiences with short lived SSD's... add up all the anecdotes and eventually you reach reality when most of the stories match...
The problem is that for each person with anecdotal evidence of SSDs failing, there's 200 other people not commenting about their entirely working SSD.
New Intel drives do, as they use the Sandforce chipset. However Samsung drives don't. Samsung makes their own controller, and they don't mess with compression. All writes are equal.
Also 14TB sounds a little low for a write limit. MLC drives, as the XM25 was, are generally spec'd at 3000-5000 P/E cycles. Actually should be higher since that is the spec for 20nm class flash and the XM25 was 50nm flash. Even assuming 1000, and assuming a write amplification factor of 3 (it usually won't be near that high) you are talking 52TB if the drive has no internal overprovisioning, which it probably does.
As an example, AnandTech tested a Samsung 840 TLC drive. The 250GB drive was able to take about 266TB of incompressible data, which translates to a bit more than 1000 P/E cycles.
If you have a high write workload, their MLC drives aren't that much. A 512GB 840 Pro drive will run you like $450. That should get you somewhere in the realm of 1.5PB of writes before it fails, maybe more.
Real-time Accelerated Processing of IO Data
Nope, definitely not contrived at all.
Ezekiel 23:20
I'd be willing to consider TLC despite its drawbacks if the price was considerably lower than with MLC-based drives, but that's currently not the case. The Samsung 840 EVO costs about $185 for the 250GB model, while the 840 Pro (using MLC) is about $230-$250. So we're talking about 75 cents a gigabyte for TLC, and about a buck a gigabyte for MLC. I'm willing to take the 25% cost hit for far better endurance. In my opinion, TLC really needs to get down to 25-40 cents a gigabyte before it would be worth it. If we could get a 640GB TLC drive in the $160-$200 price range, then that would be worth going for. But the current offerings? No.
excuse me, is this the retard thread?
world was created 5 seconds before this post as it is.
I hate to see this discussion go entirely to the "wearout" issue. Clearly there are some posters here heavily invested in spinning disk. There are more exciting flash technologies in the pipeline.
Samsung has a new flash technology for the Enterprise called 3D V-NAND. By using 24 separate layers of flash on one chip they can keep the feature size up and still keep pace with storage density. They believe they can go to hundreds of layers. There is talk of a 384GB single chip for smartphones and tablets. Not Gbit, Gigabyte.
But no, go back and forth some more about wearout rates.
Help stamp out iliturcy.
from your kind link, it looks to be doing lazy writes.