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SanDisk Extreme II SSD Review: Striking At The Heavy-Hitters

Results: Sequential Performance

Once again, we turn to Iometer to measure the most basic performance parameters.

Fantastic sequential read and write performance is a trademark of modern SSDs. To measure it, we use incompressible data over a 16 GB LBA space and then test at queue depths from one to 16. We're reporting these numbers in binary (where 1 KB equals 1024) instead of decimal (where 1 KB is 1000 bytes). When necessary, we're also limiting the scale of the chart to help readability.

128 KB Sequential Read Scaling

Just about every newer SSD ends up beyond the 500 MB/s mark with eight or 16 outstanding commands. The most notable differences come into play at lower queue depths, particularly when the queue depth is one or two.

The SanDisk drives peak past two outstanding commands, laying down a fierce 530+ MB/s. They best the next-fastest repositories, though not by much. Even at a queue depth of one, the Extreme IIs push 500 MB/s.

128 KB Sequential Write Scaling

Again, the SanDisk trio shows up swinging. The 240 and 480 GB models both touch 500 MB/s on writes, while the 120 GB version makes a splash by achieving 316 MB/s. That's actually the upper range for a 120 GB SSD, unless you're taking about a SandForce-based drive working on zero-fill data, and the most junior Extreme is on par with Intel's SSD 510 and 335 with two times the capacity.

Performance Versus Capacity

There aren't many surprises to see when we look at capacity across the LBA range. In truth, this chart should be a flat line across the entire drive. In reality, not every SSD behaves that way.

And that's exactly what we see. The Extreme IIs are seemingly wedded together, separated by just a few MB/s.

A similar story is told when we look at writes (that is to say, not a very interesting one). The larger two models are almost as quick as each other, while the 120 GB version kisses 320 MB/s. It's possible that the comparatively jagged performance line is a result of nCache.

  • Someone Somewhere
    Where's the 840/840 Pro?
    Also, you appear to have put one of the labels back on the wrong way round.
  • awez
    My thoughts exactly, where's the 840 and 840 pro?
  • boulbox
    I have always been a fan of Sandisk SSDs, can't wait until to try this out in someone else's build as they usually sell their products that is very acceptable for budgets.
  • Dixevil
    heavy hitters with no 840pro
  • slomo4sho
    I am also curious about the selection of the comparative models. Having the Extreme (not II) in the charts for comparison between the two generations would have been a welcomed addition along with the inclusion of the 840 series.
  • flong777
    I know a lot of people have already pointed this out but can't Tom's Hardware afford a damn 256 GB 840 Pro? I mean come on, it is the fastest SSD on the planet right now.
  • raidtarded
    Seriously, what is the point of this article? The fastest car in the world is as Yugo if you dont test against a Lamborghini.
  • teh_gerbil
    Why are there 2 of your most recent SSD reviews lack the Samsung 840/Pro? Are you being paid by the respective companies to avoid using them, as for both SSD's, as per other reviews I have read, the 840 Pro cr@ps all over both of them, but due to your lack of them, they're both top of your benchmarks! Very very bad benchmarking.,3517.html
  • merikafyeah
    Want an 840 Pro comparison and far more in-depth review?
    See here:
    It's Anand's new favorite SSD, and based on the results, I'm inclined to agree.
    It's peak performance is right up there with the 840 Pro, but what's really extreme is the drive's consistency. It's performance when the drive is close to full is unmatched.

    There are no high peaks accompanied by low valleys in performance when it comes to the Extreme II. It's pretty much smooth and fast sailing all the time, which in my book, places the Extreme II a step above the 840 Pro. The 840 Pro would have to be at least $30 cheaper than the Extreme II for me to even consider it over the Extreme II.
  • JPNpower
    Why is the 840 Pro the fastest SSD on the planet? It has its share of drawbacks, and is slower than the OCZ Vector, and the Plextor M5 Pro Xtreme on many benchmarks. Don't make broad statemets that aren't always true.