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An Editorial On Write Endurance

Samsung's SSD Global Summit: The Leader In NAND Speaks Up
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When Samsung launched its 840 last year, the technical press expressed concern about the write endurance of triple-level cell memory. A number of folks seemed to think that a 1000 program/erase-cycle rating meant that the 840s would start failing after a few months. Of course, we've seen that those fears were largely exaggerated. The general sentiment toward TLC NAND remains, though. Many readers who know what triple-level cell memory is, but haven't spent any time testing it, tend to distrust the technology.

If you don't think your comments are being read at a company as large as Samsung, you are mistaken.

At last year's SSD Global Summit, Samsung was very coy about its triple-level cell NAND. It didn't even want to talk about lithography. During one Q&A session with company executives, the same questions were asked multiple times before Samsung gave up some answers. Write endurance inquires were deftly deflected, too. Everyone in the room already knew that Samsung's TLC NAND was rated for ~1000 program/erase cycles, but the execs refused to confirm. They tried claiming the company's TLC-based products were on par with SSDs built using two-bit-per-cell flash on the same node. Confidence was not inspired by those responses.

This year, however, Samsung went on the offensive with TLC NAND. Even our own storage team had already taken 840s over 3000 P/E cycles before sectors started getting reallocated. So, Samsung showed us the math on how much data has to go through an 840 before it's at risk of failure. By the end, it appeared that everyone in the room believed an 840 (or 840 EVO now) offers enough write endurance headroom for most desktop applications.

As Tom's Hardware's enterprise storage editor, I discuss endurance in each of my stories. Business workloads can be downright hostile to solid-state storage. I'm talking random writes, 24 hours a day. In many applications, even eMLC NAND rated for 35,000 P/E cycles is inadequate. I've personally exhausted more MLC-based drives than I care to even think about. But I'm also a client user. I write stories, render video, edit pictures, and compile code. I've been using SSDs for years without ever measuring I/O on my personal workstation. 

What did I find when I pulled up that data? Apparently, I don't write very much to my drive. On an SSD that was in my system for two years, I had written a total of 2 TB. At that rate, Samsung's 120 GB 840 would last me more than 120 years, while the 250 GB model would have the write endurance to go 250 years. Even with write amplification factored in, you're looking at plenty of time beyond the three year warranty. 

Perhaps what Samsung knew all along was that write endurance doesn't tell the whole story of reliability. Yes, the company's triple-level cell flash has about one-third of today's MLC NAND. But does that really matter? With sales greater than 2.5 million units in 10 months, a lot of customers either don't think so or don't know any different.

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  • 0 Hide
    alchemy69 , August 8, 2013 9:17 PM
    No word on when we might be seeing the new vertical NAND in products?
  • 2 Hide
    radiovan , August 8, 2013 9:42 PM
    So, is NVMe complimentary to (the new) SATA 3.2 or it's simply playing its own fiddle?
  • 0 Hide
    ojas , August 9, 2013 1:19 AM
    Well, i have 2.3 TB of writes and 4.36 TB of reads on my 120GB Intel 320 series SSD in the last year...no re-allocated sectors thus far.

    My 840 has about 0.41TB written to it, and i bought this drive a few months ago.

    Anyway, looking forward to RAPID.
  • -3 Hide
    Someone Somewhere , August 9, 2013 2:08 AM
    @radiovan I read it as being that it's a replacement for AHCI/IDE - it'll still work with SATA.

    Anyone else find that this reads like an infomercial?
  • 0 Hide
    Steveymoo , August 9, 2013 3:52 AM
    Ahh Samsung, you're still not immune to the age old marketting technique of combining large breasted women with your technology, to catch men's eyes.
  • 1 Hide
    Onus , August 9, 2013 5:53 AM
    Organizations with huge amounts of data to sift (e.g. Google, NSA, IRS) will want any speed they can get. Labs doing FCAT testing need ridiculous write speeds. For the rest of us, as individuals, if a bloated application like Word already loads in the blink of an eye, any faster simply doesn't matter. I hope a substantial focus can be placed on cost.
  • 2 Hide
    JPNpower , August 9, 2013 6:08 AM
    CPUs GPUs are sort of slowing. this is the future. This is innovation at its hottest and fastest. Maybe it is competition as some say, as AMD is bogged down in processors, giving the leaders a healthy lead, but in flash, Samsung, Sandisk/Toshiba, and Micron are hot at it.

    Everyone wins.
  • 0 Hide
    Lord_Kitty , August 9, 2013 6:30 AM
    In other words, Samsung is taking over the world, along with Intel and Google.
  • 2 Hide
    jabliese , August 9, 2013 7:30 AM
    radiovan and Someone

    NVMe is a protocol to work with PCIe. This is quite clear from the slides. What is PCIe? Do you remember your last video card upgrade? The slot your card plugged into was most likely a PCIe slot. NVMe has no business with SATA, and that's the way you want it to be.
  • 0 Hide
    drewriley , August 9, 2013 8:16 AM
    Quote:
    No word on when we might be seeing the new vertical NAND in products?


    Last year, Samsung touched on some new technologies that they were working on, but didn't share any insight during their latest summit,
  • -1 Hide
    master9716 , August 9, 2013 10:50 AM
    180 BILLION! in revenue , Wonder if they pay their employees mcdonals salary and rake in the cash for the ceos' Koreans are taking over , they have surpassed the japanese.
  • 0 Hide
    radiovan , August 9, 2013 11:19 AM
    Quote:
    radiovan and Someone

    NVMe is a protocol to work with PCIe. This is quite clear from the slides. What is PCIe? Do you remember your last video card upgrade? The slot your card plugged into was most likely a PCIe slot. NVMe has no business with SATA, and that's the way you want it to be.

    ...SATA 3.2 (SATA Express) uses PCIe lanes (2x PCIe 3.0) to provide faster communication between the CPU and the storage media, hence reducing the bottleneck. I understand NVMe is an independent tech from SATA 3.2 (notice that ".2" behind the 3).

    *** Edited by Moderator ***
  • 4 Hide
    drewriley , August 9, 2013 11:54 AM
    Quote:
    So, is NVMe complimentary to (the new) SATA 3.2 or it's simply playing its own fiddle?


    That's a solid question and one that isn't always easy to answer. There are so many new interfaces and protocols, it's hard to keep them all straight. To answer your question, SATA 3.2 now includes SATA Express. SATA Express is a standard that defines two driver interfaces and two physical interfaces. You can connect via legacy SATA or PCIe. For SATA, you will use the AHCI interface. In this way, it will work just like every other SATA SSD that is on the market. For PCIe, the driver interface is either AHCI or NVMe. With AHCI, you still see a PCIe device dangling off of the PCIe root port and you use the same AHCI drivers that comes with your operating system of choice. With NVMe, you get all of the added benefits of the new protocol, but you will need OS driver support. All of that should *crosses fingers* be ironed out in the next year.

    What makes things slightly confusing is that any of these combinations are valid, so you have to pay particular attention to whether your M.2 card is SATA or PCIe, and if it is PCIe, whether it is AHCI or NVMe. If you want more information, I recommended looking at the SATAIO page, they have a lot of good information. https://www.sata-io.org/sata-express
  • 0 Hide
    Heavensrevenge , August 9, 2013 2:33 PM
    Quote:
    RAPID is currently only enabled in Windows, but will be available for all 840-series drives once Samsung's Magician 4.2 software is released.


    My 840 Pro 256GB doesn't allow for RAPID even while using Samsung Magician 4.2 :( 
    It passes the Genuine Validation check and everything so I don't think this is true, or I'm an unlucky bloke.
    Does anyone have an answer as to why this is?
  • 0 Hide
    Onus , August 9, 2013 3:25 PM
    Are your SATA ports in AHCI mode, or RAID mode? In RAID mode, Samsung Magician won't work with my 830.
  • 0 Hide
    Heavensrevenge , August 9, 2013 3:42 PM
    Quote:
    Are your SATA ports in AHCI mode, or RAID mode? In RAID mode, Samsung Magician won't work with my 830.


    This should be able to clarify :) 




    Any ideas fellas?
  • 0 Hide
    radiovan , August 9, 2013 4:47 PM
    Quote:
    Quote:
    So, is NVMe complimentary to (the new) SATA 3.2 or it's simply playing its own fiddle?


    That's a solid question and one that isn't always easy to answer. There are so many new interfaces and protocols, it's hard to keep them all straight. To answer your question, SATA 3.2 now includes SATA Express. SATA Express is a standard that defines two driver interfaces and two physical interfaces. You can connect via legacy SATA or PCIe. For SATA, you will use the AHCI interface. In this way, it will work just like every other SATA SSD that is on the market. For PCIe, the driver interface is either AHCI or NVMe. With AHCI, you still see a PCIe device dangling off of the PCIe root port and you use the same AHCI drivers that comes with your operating system of choice. With NVMe, you get all of the added benefits of the new protocol, but you will need OS driver support. All of that should *crosses fingers* be ironed out in the next year.

    What makes things slightly confusing is that any of these combinations are valid, so you have to pay particular attention to whether your M.2 card is SATA or PCIe, and if it is PCIe, whether it is AHCI or NVMe. If you want more information, I recommended looking at the SATAIO page, they have a lot of good information. https://www.sata-io.org/sata-express

    Thank you for addressing my query.
  • 1 Hide
    cryan , August 9, 2013 8:34 PM
    Quote:
    Quote:
    Are your SATA ports in AHCI mode, or RAID mode? In RAID mode, Samsung Magician won't work with my 830.


    This should be able to clarify :) 

    Any ideas fellas?


    There is a note on the Samsung Magician download page ATM:

    * Notice : Official release of Magician 4.2 will be tentatively postponed until late August in order to ensure compatibility with all devices.

    My early release of 4.2 didn't support the 840 Pro, and I seemed to recall Samsung saying that the 840 Pro would get a FW upgrade that would let it use RAPID (but don't quote me on this). Or, it's just that they couldn't work out the kinks, and you'll have to wait until later this month for a fixed version.

    I know RAPID doesn't work on my 840 Pros with the 4.2 Beta that I used in the EVO review.


    Regards,
    Christopher Ryan

  • 0 Hide
    Heavensrevenge , August 9, 2013 9:36 PM
    Quote:

    There is a note on the Samsung Magician download page ATM:

    * Notice : Official release of Magician 4.2 will be tentatively postponed until late August in order to ensure compatibility with all devices.

    My early release of 4.2 didn't support the 840 Pro, and I seemed to recall Samsung saying that the 840 Pro would get a FW upgrade that would let it use RAPID (but don't quote me on this). Or, it's just that they couldn't work out the kinks, and you'll have to wait until later this month for a fixed version.

    I know RAPID doesn't work on my 840 Pros with the 4.2 Beta that I used in the EVO review.

    Regards,
    Christopher Ryan



    Isn't that something... my magician actually got notified and auto-updated lol, I don't have an EVO since RAPID would probably work if I did, and the download page DID have 4.2 on there a few days ago so it I guess they reverted their decision to offer 4.2 to download.
    I did know that reviews stated their 840 Pro's weren't detected in 4.2 to allow enabling RAPID but since it was an auto-update, I was under suspicion it was a minor version updated vs the 4.2 software included in the EVO packaging which allowed enabling of RAPID from being an official update for me.
    Ill give a screeny & checksum of my magician installer in-case anyone want to see vs theirs since I don't think this is 4.2 Beta. And if anyone wants I can upload it for others to download.



    Guess I'll need to wait for Magician 4.2.1/4.3 or a FW update then.

    Good to know I wasn't preventing it's ability to update, and that it's still incompatible at the moment.

    Thank you for the verification :) 
  • 0 Hide
    cryan , August 10, 2013 1:45 AM
    Quote:
    Quote:

    There is a note on the Samsung Magician download page ATM:

    * Notice : Official release of Magician 4.2 will be tentatively postponed until late August in order to ensure compatibility with all devices.

    My early release of 4.2 didn't support the 840 Pro, and I seemed to recall Samsung saying that the 840 Pro would get a FW upgrade that would let it use RAPID (but don't quote me on this). Or, it's just that they couldn't work out the kinks, and you'll have to wait until later this month for a fixed version.

    I know RAPID doesn't work on my 840 Pros with the 4.2 Beta that I used in the EVO review.

    Regards,
    Christopher Ryan



    Isn't that something... my magician actually got notified and auto-updated lol, I don't have an EVO since RAPID would probably work if I did, and the download page DID have 4.2 on there a few days ago so it I guess they reverted their decision to offer 4.2 to download.
    I did know that reviews stated their 840 Pro's weren't detected in 4.2 to allow enabling RAPID but since it was an auto-update, I was under suspicion it was a minor version updated vs the 4.2 software included in the EVO packaging which allowed enabling of RAPID from being an official update for me.
    Ill give a screeny & checksum of my magician installer in-case anyone want to see vs theirs since I don't think this is 4.2 Beta. And if anyone wants I can upload it for others to download.



    Guess I'll need to wait for Magician 4.2.1/4.3 or a FW update then.

    Good to know I wasn't preventing it's ability to update, and that it's still incompatible at the moment.

    Thank you for the verification :) 


    Yeah, it seems as though it was pulled. The version most reviewers were supplied with was basically just a 4.2 preview.

    The 830 and 470 won't be getting any more FW updates, but the 840 lines should be getting new FW over the next couple weeks/months. I believe most 840 EVOs will be available on the 20th, so its possible that the new updated version of Magician will coincide with the launch -- though the early retail packaging I have included 4.1 on the software CD. I'd expect most retail 840 EVOs will have new firmware and a new Magician version to download.

    It would be incredibly awesome if the 830 could get RAPID too, though.


    Regards,
    Christopher Ryan
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