A few weeks ago I mentioned on twitter that I had a new favorite SSD. This is that SSD, and surprisingly enough, it’s made by SanDisk.

The SanDisk part is very unexpected, because until now SanDisk hadn’t really put out a very impressive drive. Much like Samsung in the early days of SSDs, SanDisk is best known for its OEM efforts. The U100 and U110 are quite common in Ultrabooks, and more recently even Apple adopted SanDisk as a source for its notebooks. Low power consumption, competitive pricing and solid validation kept SanDisk in the good graces of the OEMs. Unfortunately, SanDisk did little to push the envelope on performance, and definitely did nothing to prioritize IO consistency. Until now.

The previous generation SanDisk Extreme SSD used a SandForce controller, with largely unchanged firmware. This new drive however moves to a much more favorable combination for companies who have their own firmware development team. Like Crucial’s M500, the Extreme II uses Marvell’s 88SS9187 (codename Monet) controller. SanDisk also rolls its own firmware, a combination we’ve seen in previous SanDisk SSDs (e.g. the SanDisk Ultra Plus). Rounding out the nearly vertical integration is the use of SanDisk’s 19nm eX2 ABL MLC NAND.

This is standard 2-bit-per-cell MLC NAND with a twist: a portion of each MLC NAND die is set to operate in SLC/pseudo-SLC mode. SanDisk calls this its nCache. The nCache is used as a lower latency/higher performance write buffer. In the Ultra Plus, I pointed out that there simply wasn’t much NAND allocated to the nCache since it is pulled from the ~7% spare area on the drive. With the Extreme II SanDisk doubled the amount of spare area on the drive, which could impact the size of the nCache.

SanDisk Extreme II Specifications
  120GB 240GB 480GB
Controller Marvell 88SS9187
NAND SanDisk 19nm eX2 ABL MLC NAND

128MB DDR3-1600

256MB DDR3-1600
512MB DDR3-1600
Form Factor 2.5" 7mm
Sequential Read


Sequential Write
4KB Random Read
4KB Random Write
Drive Lifetime 80TB Written
Warranty 5 years

Some small file writes are supposed to be buffered to the nCache, but that didn’t seem to improve performance in the case of the Ultra Plus, leading me to doubt its effectiveness. However, SanDisk mentioned the nCache can be used to improve data integrity as well. The indirection/page table is stored in nCache, which SanDisk believes gives it a better chance of maintaining the integrity of that table in the event of sudden power loss (since writes to nCache are quicker than to the MLC portion of the NAND). The Extreme II itself doesn’t have any capacitor based power loss data protection.

Don't be too put off by the 80TB of drive writes rating for the drives. The larger drives should carry higher ratings (and they will last longer), but in order to claim a higher endurance SanDisk would have to actually validate to that higher endurance specification. For client drives, we often times see SSD vendors provide a single endurance rating in order to keep validation costs low - despite the fact that larger drives will be able to sustain more writes over the lifetime of the drive. SanDisk offers a 5 year warranty with the Extreme II.

Despite the controller’s capabilities (as we’ve seen with the M500), SanDisk’s Extreme II doesn’t enable any sort of AES encryption or eDrive support.

With the Extreme II, SanDisk moved to a much larger amount of DRAM per capacity point. Similar to Intel’s S3700, SanDisk now uses around 1MB of DRAM per 1GB of NAND capacity. With a flat indirection/page table structure, sufficient DRAM and an increase in spare area, it would appear that SanDisk is trying to improve IO consistency. Let’s find out if they have.

Performance Consistency
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  • dsumanik - Tuesday, June 4, 2013 - link

    The benches on this drive are good.....not great, and I don think the opening bias is necessary. Who runs any disk at capacity 24/7? Perhaps some people temporarily... But 24/7 drive full???

    Only a fool.

    Kudos to sandisk for making a competitive offering, but please anandtech keep the bias out of the reviews....specially when it's not warranted.

    Storage bench is great, but it's not the only metric.

    Haswell is good, not great. But if your rocking a 2600k from 2 years ago? Meh.

    Where are the legendary power savings? Why don't we have 4 ghz + skus? 8 cores? 64gb ram support? Quick sync degraded lol!! Good job on iris pro. Why can't I buy it and slap it into an enthusiast board?

    Yet you read this review and the haswell review and come away feeling positive.

    Real life:

    A mild upgrade in IPC, higher In use TDP, 2 year old CPU's are still competitive

    Mixed bag of results, on unproven firmware.
  • Death666Angel - Tuesday, June 4, 2013 - link

    Why do you keep ignoring the Samsung 840 Pro with spare area increased when it comes to consistency. It seems to me to be the best drive around. And if you value and know about consistency it seems pretty straight forward to increase the spare area and you should have the abilities to do so as well.
  • seapeople - Wednesday, June 5, 2013 - link

    Agreed, it looks like a Samsung 840 Pro that's not completely full would be the performance king in every aspect - most consistent (check the 25% spare area graphs!), fastest in every test, good reliability history, and the best all around power consumption numbers, especially in the idle state which is presumably the most important.

    Yet this drive is virtually ignored in the review, other than the ancillary mention in all the performance benchmarks it still wins, "The SanDisk did great here! Only a little behind all the Samsung drives... and as long as the Samsung drives are completely full, then the SanDisk gets better consistency, too! The SanDisk is my FAVORITE!"

    The prevailing theme of this review should probably be "The SanDisk gives you performance nearly as good as a Samsung at a lower price." Not, "OMG I HAVE A NEW FAV0RIT3 DRIVE! Look at the contrived benchmark I came up with to punish all the other drives being used in ways that nobody would actually use them in..."

    Seriously, anybody doing all that junk with their SSD would know to partition 25% of spare area into it, which then makes the Samsung Pro the clear winner, albeit at a higher cost per usable GB.
  • FunBunny2 - Tuesday, June 4, 2013 - link

    To the extent that "cloud" (re-)creates server-dense/client-thin computing, how well an SSD behaves in today's "client" doesn't matter much. Server workloads, with lots o random operations, will be where storage happens. Anand is correct to test SSDs under loads more server-like. As many have figured out, HDD in the enterprise are little different from consumer parts. "Cloud" vendors, in order to make money, will segue to "consumer" SSD. Thus, we do need to know how well they behave doing "server" loads; they will in any case. Clients will come with some amount flash (not necessarily even on current file system protocols).
  • joel4565 - Tuesday, June 4, 2013 - link

    Any word on whether this drive will be offered in a 960 GB capacity for a reasonable price in the near future?

    This looks like the best performing drive yet reviewed, but I doubt I will see that big of difference from my 120 GB Crucial M4 in day to day usage. I really don't think most of us will see a large difference until we go to a faster interface.

    So unless this drastically change in the next few months, I think my next drive will be the Crucial M500 960GB. Yes it will not be as consistent or quite as fast as the SanDisk Extreme II, but I won't have to worry about splitting my files, or moving steam games from my 7200 rpm drive to the SSD if they have long load times.
  • clepsydrae - Wednesday, June 5, 2013 - link

    Question for those more knowledgeable: I'm building a new DAW (4770k, win 8) which will also be used for development (Eclipse in linux). Based on earlier anandtech reviews I ordered a 128GB 840P Pro for use as the OS drive and eclipse workspace directory and the like. Reading this article, i'm not sure if I should return the 840P for the SanDisk... the 840P leads it in almost all the metrics except the one that is the most "real-world" and which seems to mimic what I'll be using it for (i.e. Eclipse.)

  • bmgoodman - Wednesday, June 5, 2013 - link

    I gave up on SanDisk after they totally botched TRIM on their previous generation drive. They did such a poor job admitting it and finally fixing it that it left a bad taste in my mouth. They'd have to *give* me a drive for me to try their products again.
  • samster712 - Friday, June 7, 2013 - link

    So would anyone recommend this drive over the 840pro 256? Im very indecisive about buying a new drive.
  • Rumboogy - Thursday, July 11, 2013 - link

    Quick question. You mentioned a method to create an unused block of storage that could be used by the controller by creating a new partition (I assume fully formatting it) and then deleting it. This assumes TRIM marks the whole set of LBAs that covered the partition as being available. What is the comparable procedure on a Mac? Particularly if you don't get TRIM by default. And if you do turn it would it work in this case? Is there a way to guarantee you are allocating a block of LBAs to non-use on the Mac?
  • pcmax - Monday, August 12, 2013 - link

    Would have been really nice to compare it to their previous gen the Extreme I?

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