DRAM-less SSDs

Discussion in 'Computer Memory and Hard Drives' started by OmniDyne, Mar 1, 2018.

  1. OmniDyne

    OmniDyne Active Member

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    562
    I watched a video of Linus Tech Tips talk about DRAM-less SSDs. Subsequently I started reading articles from numerous sites that had benchmarked DRAM-less SSDs and SSDs with the DRAM cache.

    Linus and Tom's Hardware spelled doom for DRAM-less SSDs, stating that lower life and a lower warranty are the result of removing the DRAM cache, on top of 'lesser' performance.

    Every SSD I've seen, DRAM or no DRAM, has a 3 year warranty, whether it's a pricier EVO or a cheaper Kingston.

    I purchased a 120GB Sandisk without DRAM, threw the OS on it, and it was life changing for me.

    Do anyone of you have experience with either type of SSD? Is there a real world performance difference, or is this an enthusiast sector issue?
     
  2. Okedokey

    Okedokey Well-Known Member

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    9,506
    Nothing you're ever going to notice. I think it is analogous to fragmentation these days. Ideally its not there, however in the average to power user case, virtually negligible.
     
  3. Intel_man

    Intel_man VIP Member

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    5,709
    Buying a sata SSD is no longer considered "enthusiast". Just fyi.
     
    _Kyle_ likes this.
  4. OmniDyne

    OmniDyne Active Member

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    Ha well DRAM cache applies to M.2 NVMe.
     
  5. Intel_man

    Intel_man VIP Member

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    5,709
    Yes and?

    The numbers to look out for to determine the reliability of a ssd isn't if it's DRAM or DRAM-less. Look into the MTBF (mean time before failure), TBW (terabytes written), and DWPD (drive writes per day). A good indication of a reliable product is also the warranty. Also, you've clearly not looked hard enough if you've only found 3 year warranty drives because the 850 EVO you even mentioned sports a 5 year warranty and depending on the size of the drive ranges from 75 TBW to 300TBW endurance.

    If you're talking about performance, DRAM and DRAM-less is not your major concern. The type of NAND Flash is of greater concern for you when it comes to SATA SSDs. SLC, MLC, and TLC is what you should be looking at when comparing those drives. Preferably, you'd want SLC flash, but they're feasible for the capacity that everyone wants them in. So typically, you'll only find them as ssd buffers within the SSD itself. The higher performance SATA ssd drives would use MLC flash, and most budget drives would be on the TLC flash which is slower. Don't confuse those flash types with 3D Nand flash, which is just stacking layers of MLC or TLC flash on top of one another.
     
  6. Darren

    Darren Moderator Staff Member

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    12,091
    Welp. Guess I need a new hobby.
     
    _Kyle_ likes this.
  7. OmniDyne

    OmniDyne Active Member

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    562
    http://www.tomshardware.com/reviews/dramless-ssd-roundup,4833.html

    "In effect, the operating system has one map of data addresses where it thinks the data is located, which the SSD considers the logical map, while the SSD has its own physical map that reflects where data is actually located. The SSD maintains the two separate maps, and it references or updates the maps every time the operating system needs to access data. The Flash Translation Layer (FTL) coordinates all of the processes.

    "Unfortunately, DRAMless SSDs also have a sinister side. Updating the map directly on the flash requires small random writes, which takes a bite out of the SSD's endurance. This is a particularly vexing issue with low endurance planar 2D TLC NAND flash."

    http://www.tomshardware.com/reviews/dramless-ssd-roundup,4833.html


    "It's true that the drives are faster than a hard disk drive, but when you lean on them with a slightly elevated workload, they can stall, stutter, and deliver a worse user experience than you would get with a spinning mechanical disk."




     
  8. Intel_man

    Intel_man VIP Member

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    Ok. Do you know what the quotes mean that you took from Tom's Hardware? You're quoting without context and understanding on what I'm trying to discuss.
     
  9. OmniDyne

    OmniDyne Active Member

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    I did not ask about flash types. I asked about DRAM. I didn't need information on flash types. I asked if anyone in this forum had experience with any type of SSD without DRAM.

    I then asked if this was a real world performance issue, meaning will everyday tasks be affected by a DRAM-less SSD, or is is DRAM something an enthusiast should worry about.

    You then stated state that DRAM wasn't a major concern for performance or reliability. Tom's Hardware and Linus might disagree, which was the entire reason I created the thread in the first place.

    In fact, Tom's Hardware stated they wouldn't recommend a DRAM-less SSD with MLC flash as an entry level drive. Linus said the same.
     
    Last edited: Mar 7, 2018
  10. Intel_man

    Intel_man VIP Member

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    5,709
    If you follow what I wrote on what to look out for in reliability, you would have tossed out the DRAMless drives when you do your research before buying.

    It really isn't though if you did the research and looked at the benchmarks that get posted by anandtech. They have some fairly thorough tests on sequential and random read/writes. The 4KB tests they do a series of different queue depths would indicate the struggles in a DRAMless ssd. What I'm trying to get across was that judging a drive purely on the DRAM vs DRAM-less can be misleading.
     
  11. OmniDyne

    OmniDyne Active Member

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    562
    Absolutely. I unfortunately didn't see any articles on DRAM before I purchased the drive. Where did you write about DRAM? I scanned the forum looking for information on DRAM before posting, I must have missed it.

    I did research before my purchase. The articles I found only mentioned memory type. That's why I purchased a drive with MLC.

    Anandtech honestly never showed in my results when researching. That will be something I look for in the future.
     

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