Intel SSD 910 Review: PCI Express-Based Enterprise Storage

Write Endurance

Most folks will never even come close to exceeding the write endurance limits of today's desktop-oriented SSDs. Write exhaustion requires continuous writing to a drive for weeks and months on end before you completely exhaust the usable life of each NAND cell. 

In the enterprise world, however, this is a much more likely scenario. Knowing the write endurance of an SSD can help IT professionals select drives that are best suited to their tasks.

When Intel released its first enterprise drive, X25-E, the company did not publicly state write endurance specifications. With its two subsequent offerings, though, Intel was very specific about what results were achievable and how to achieve them. The 400/800 GB versions of the Intel SSD 910 have a stated write endurance of 7 and 14 PB, respectively. According to Intel, write endurance is measured while running 100% random 4 KB and 8 KB writes spanning 100% of the SSD using Iometer. This is, by far, the worst-case scenario. In a mixed workload, you'd see more favorable results, as we will see.

Before we dig into the results, if you are unfamiliar with the different types of NAND or the concept of write exhaustion in general, take a look at our reviews of the Toshiba MK4001GRZB and Intel SSD 710

To test write endurance, we wrote large block, sequential data to the drive, while continuously monitoring the MWI (Media Wearout Indicator).  The MWI reports, from 0-100, the percentage of life that has been used on the drive. We started with a clean drive and wrote to it until the MWI reached 1%. It should be noted that each of the four NAND modules has its own MWI. The data below is based on when the first module reported a change to the MWI. The other three modules all changed within ~150 GB of the first. This difference only accounted for ~0.15% of the total number of writes.

By writing sequential data, we are showing the maximum usable life of the NAND itself, removing outside factors like wear-leveling and garbage collection. In this configuration, the write amplification should be very close to 1.0.

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Endurance RatingSequential Workload, QD=1, 8 MB, RandomIntel SSD 910Intel SSD 710Intel X25-EToshiba MK4001GRZB
NAND TypeIntel 25 nm eMLC (HET)Intel 25 nm eMLC (HET)Intel 50 nm SLCToshiba 32 nm SLC
RAW NAND Capacity896 GB320 GB77GB512 GB
IDEMA Capacity (User Accessible)800 GB200 GB64 GB400 GB
P/E Cycles Observed (IDEMA)46 33936 600237 968225 064
P/E Cycles Observed (Raw)41 37422 875198 307175 831
Host Writes per 1% of MWI370.71 TB73.20 TB152.3 TB900.2 TB

In terms of P/E cycles observed, the Intel SSD 910 outperforms Intel's SSD 710 by 80%, even though they use the same NAND. But, as with all MLC-based flash, it can’t really hold a candle to good old-fashioned SLC. 

So why, in an enterprise application, where write endurance is so important, would you consider anything other than SLC? Simply, cost. HET MLC (or eMLC) offers a solid middle-ground to those that need enterprise-level write endurance, but can’t justify the price of SLC-based drives. Intel's SSD 910 makes that value proposition even more intriguing compared to its SSD 710. 

When you look at just write endurance and cost ($/PB-written), ignoring all other factors, the SLC-based X25-E is still the clear winner. But the comparison to the SSD 910 is much better-looking than the SSD 710. This is important for customers who want to use these drives purely as write-caching devices, where speed and size can be secondary features.

  • that is one fast Sequential read speed. It to bad that they will be $1000+ market and out of reach of all but the server/ workstation crowd
  • The OCZ is tested with compressible data? talk about best case scenario. what were the incompressible results like?
  • s3anister
    PCI-E Solid State Storage is great but I can't help but wonder; where is the Memristor? The true performance gains to be had are with massive RAM-disks that aren't volatile.
  • apache_lives
    The most important and un-comparable factor here is 5 years later those Intel SSD's will still be functional, any other brand im surprised they last 5 months in normal machines with the failure rates i have seen first hand - OCZ, GSkill etc there all horrible i bought an Intel SSD for this reason - THEY WORK.

    Review sites never cover real world use - that is to live with it day in day out (reliability), its not all about raw speed and performance.
  • ZakTheEvil
    Yeah, consumer SSD reliability is a bit of disappointment. At best they seem to be as reliable as hard drives.
  • georgeisdead
    This is a note to address several articles I have come across lately that state intel's reputation for quality and reliability in the SSD market as if it is a given. These comments are from my personal experience with intel's drives. I have owned 3 intel solid state drives, one X25-M G1, and two X25-M G2's. The X25-M G1 failed after 2 years while one of the G2 drives failed after 2.5 years. Now, I am not an expert on MTBF and reliability, but in my opinion this is a pretty poor track record. It is entirely possible that this is a coinicidence, however both drives failed in the same manner, from the same problem (determined by a third party data recovery specialist): Bad NAND flash.

    As best I understand it as it was descibed by the company that analyzed these failed drives, a block of NAND flash either went bad or became inaccessible by the controller rendering the drives useless and unable to be accessed by normal means of hooking it up to a SATA or USB port. Two drives, different NAND (50 nm for the G1 and 34 nm for the G2), same failure mode.

    Once again, this is not definitive, just my observations but to me, I think review sites need to be a little more cautious about how they qualify intel's reputation for quality and reliability because from my perspective, intel has neither and I have since began using crucial SSD's. Hopefully, I will see much longer life from these new drives.
  • jdamon113
    I would like to see something like this stacked in our EMC, Could this drive with a rack of othere just like it, run 24/7 for 3 + years, Sure we replace a drive here and there in our EMC, but the unit as a whole has never went down in its 5 year life.
    Intel, you should test these drive in that real world application. EMC, VM-ware and several data bases carve out some LUN's and Push the envelope. In this situation, should the device prove worthy, the 4000 price tag will come down very fast, and the data center will put it trust in product, So for those reading this for your personal home workstation and gaming ridge, you need not apply in this arena.
    Intel is just about 18-months 2 years of owning the data center, Even EMC is powered by intel.
  • jaquith
    Enterprise e.g. SQL you need SLC otherwise you'd be making a career replacing drives. The cost is down time and replacement. I can write more 'stuff' but it's that simple. For our IDX and similar read data it about reliability and capacity.
  • willard
    razor7104that is one fast Sequential read speed. It to bad that they will be $1000+ market and out of reach of all but the server/ workstation crowdThat's because this was not designed for consumers. It's not like they're marking the price up 1000% for shits and giggles. Enterprise hardware costs more to make because it must be much faster and much more reliable.

    This drive, and every other piece of enterprise hardware out there, was never meant to be used by consumers.
  • drewriley
    jimbob rubaeThe OCZ is tested with compressible data? talk about best case scenario. what were the incompressible results like?
    Check out the Sequential Performance page, lists both compressible and incompressible. For all the other tests, random (incompressible) data was used.