Why SSDs are obsolete

“SSDs were built because there are billions of SATA and SAS disk ports available,” Robin Harris writes for ZDNet. “Filling some of those ports with SSDs promised to be quite profitable – a promise fulfilled in the last 5 years.”

“But now that non-volatile memory technology – flash today, plus RRAM tomorrow – has been widely accepted, it is time to build systems that use flash directly instead of through our antique storage stacks,” Harris writes. “The various efforts to decrease latency – SATA 3, NVMe, and others – still add layers of software between our applications and our data, creating complexity and wasting CPU cycles.”

“SSDs are obsolete in an architectural, not functional, sense,” Harris writes. “We need to incorporate flash and, soon, byte-addressable NVM memory, as they are, rather than making them seem like disks. This is no small effort, but with the slowing of processor performance increases, systems need to find performance elsewhere. The storage stack is ripe for disruptive improvement.”

Read more in the full article here.


  1. Really? NVM memory. …The department of redundancy department.

    NVM = Non-volatile memory

    Like saying NIC card.



    Dave Luxem
    Senior Sales Advisor | Zones, Inc.
    253-205-3414 | Fax: 253-205-2414 | dave.luxem@zones.com | zones.com

    1. Wow, I don’t think I can recall too many instances of someone giving their real name first and last names, and enough contact information on an open forum.

      That’s pretty wild.

      1. Don’t forget MIDI interface.

        The acronym becomes synonymous with the technology, so the redundancy in naming the hardware from which the tech derives its name is common. I feel your pain, though.

    2. ever try reading a BACN graph (pre EGG) for redundancy and unneeded repetition? drives you nuts and a little crazy too!

      Btw, i too have no problem using my real name on this forum.

    3. Hey Dave:

      — Looking up the definition of NVM on the net: Helpful

      — Having reached your current age and still remembering what a NIC is: Impressive

      — Being so asinine as to include your entire contact card info on an open forum, thereby proving to the entire world how incredibly narcissistic you are: PRICELESS!

  2. This could finally end the confusion many people have over the term “memory”. To non-techies it means something to be “remembered” in a semi-permanent state and recalled later… i.e. *storage*. Unfortunately, in computer terms memory is the actual working space, stuff doesn’t stay in it for very long, and is lost whenever you shut down or restart.

  3. Yes, for the top of the line SSDs (and most SSDs in typical RAID configurations) SATA and similar interfaces are becoming a bottleneck. (High end SAS and others like it still have a bit of headroom — but not for long.)

    The real solution (for the next 5+ years) is to do it by direct PCIe interfaces.

    While SATA III is limited to a theoretical peak of about 0.75 GB/sec, even PCIe 3.0 with only two lanes or PCIe 2.0 with four lanes (a typical minimum configuration of most PCIe based SSDs today) has a theoretical peak of 1.97 GB/sec (2.0 GB/sec for four lanes PCIe 2.0)– over 2.6 times the throughput. Once PCIe 4.0 is deployed and SSDs standardize on 4 lanes minimum the theoretical peak goes to 7.88 GB/sec. And the really fast, large RAIDs could go to 16 lanes for a theoretical peak of 31.5 GB/sec (moving a TB in about a minute). I don’t see anyone needing more than that in the near future.

    Want a 4 TB SSD (or 16 TB SSD RAID) that is four lanes PCIe 4.0 for a reasonable price? Just wait a couple years. It will be there.

    We just need to use the standards that are currently available and near term. This is why Apple’s using a PCIe interface for many of its SSD implementations — even though they’re currently PCIe 2.0. Hopefully, they’ll move everything to PCIe 3.0 and 4.0 (when that standard is finalized) in the not too distant future.

    1. I have never seen this happen and suspect there were other OS/App problems with the Mac that slowed it down that much. I suspect that Activity Monitor would quickly show what was eating up CPU capacity.

      The first MBPro I converted from 7200 rpm HD to SSD was 2010 and boot time went from about 1.25 minutes to about 30 seconds for a cold boot. Later SSDs have become faster yet.

      A tech guy can diagnose what is going on booting from an external SSD in a few minutes.

  4. This guy does not understand the underlying technology. The same thing that makes NVM inexpensive, forces it to be block addressable and required extensive block ECC coding to address errors. Byte addressable memory is significantly less dense for a reason. Both exist and will be around, neither with replace the other.

    1. i.e. is a device physics issue. The way transistors are layed out across word lines and byte lines in the NAND arrays. Byte addressable NVM memory will track closer to DRAM in pricing (think RRAM, PCM, etc).

  5. Many are confused by the difference between SSD hard drives and flash hard drives. This should clear it up.


    SSD stands for Solid State Disk, and it means storage that doesn’t require moving parts. This concept has been around for decades, and originally it was RAM-based, i.e. the storage was similar to today’s regular computer memory. This means it was volatile, so it required that power was continuously applied or the data would be lost.

    Flash storage is also relatively old technology, but started as a way to permanently store information without power being applied.

    Flash storage has traditionally had significant aging issues. Basically you could only write to the memory a certain number of times before you would lose that section of the drive, and performance would generally get worse over time as well.

    As these issues with Flash storage started getting better (in the late 2000’s), manufacturers started making SSDs out of Flash memory instead of out of RAM.

    Modern SSD hard drives are Flash-based, so today there’s not really a difference today between SSD and Flash. SSD is simply a disk that doesn’t have moving parts, and Flash is the implementation that allows that to happen.

    USB thumb drives have used Flash storage for a long time as well, but the quality of the Flash storage in those is typically much lower than the Flash memory used in SSDs. This means much worse performance, etc.


    SSD just means a hard disk that doesn’t move
    Flash is a type of memory that is very fast and doesn’t require continuous power (non-volatile)
    SSDs used to use RAM, but now use Flash instead
    In short, you shouldn’t compare Flash to SSD just as you shouldn’t compare batteries to lithium-ion. In both cases the latter is a type of the former.

  6. Have an SSD plugged in to a PCIe slot instead of a sata port in my 2009 Mac Pro. It’s much faster to start than the 7200RPM hybrid HDD.

    Someday I’ll drop one in my 17″ MBP, too.

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