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SanDisk Extreme II SSD Review
Date: Jun 14, 2013
Author: Marco Chiappetta
Introduction and Specifications

Odds are, if you’ve bought anything that uses flash memory in the last 20 years or so, you already own a small piece of SanDisk technology. The company has been a leader in flash memory storage since the late ‘80s and manufactures products used in everything from smartphones and portable media players to digital cameras and camcorders. With such a long history in the flash memory business, it’s should be no surprise that SanDisk offers an array of solid state storage solutions for desktop and mobile PCs as well. In fact, SanDisk recently expanded their product stack with some new, high-performance SSDs that leverage the company’s own NAND flash memory and Marvel’s popular 88SSS9187 controller. The new drives are members of SanDisk’s Extreme II family of products and target PC enthusiasts, gamers, and multi-media aficionados.

We’ve got a trio of SanDisk’s Extreme II drive in hand and will how you how they perform versus a number of competing products on the pages ahead. Before we get to the numbers though, below are the main features and specifications for the SanDisk’s Extreme II drives, followed by a teardown of one of one of the drives. Check out the good and then we’ll move on and see how the drives measure up...

SanDisk Extreme II SSD
Specifications & Features

Priced as low as $139 on Amazon - $449 - 480GB As Tested


The initial line-up of SanDisk Extreme II solid state drives will consist of 120GB, 240GB, and 480GB models. The specifications for the three drives are listed in the chart above, and we’ll be testing all three on the pages ahead. As you can see in the chart, expected read performance is similar for all three drives at 545MB/s – 550MB/s. Write performance between the 240GB and 480GB drives differs by only 10MB/s (510MB/s vs. 500MB/s), though the 120GB drive tops out at 340MB/s.

All three of SanDisk’s initial Extreme II series drives conform to the standard 2.5” form factor and are only 7mm thick. They have basic enclosures made of a plastic composite material, with decals top and bottom—one with the branding on top and another on the bottom that lists the drive specifications and model numbering, etc.


A Look Inside The SanDisk Extreme II SSD

Inside the drives you’ll find an array of SanDisk-made 19nm eX2 ABL MLC NAND flash memory, an 8-channel Marvell 88SSS9187 controller with SATA 6Gbps interface, and a DDR3 DRAM cache. The 120GB drive features 128GB of total NAND flash memory, the 240GB drive features 256GB, and the 480GB drive features 512GB. The additional ~7% of unused NAND is reserved for wear leveling and other maintenance operations. The size of the DRAM cache on the drives differs as well, with 128MB, 256MB, and 512MB capacities for the 120GB, 240GB, and 480GB drives, respectively.

In addition to the DRAM cache, SanDisk also employ a proprietary technology dubbed nCache in the Extreme II drives. The nCache is actually a chunk of the MLC NAND that operates in an SLC-like mode. SanDisk’s nCache technology accumulates small writes in the non-volatile nCache, and consolidates them before flushing them to the larger MLC NAND flash. This multi-tiered caching approach is designed to improve random write performance and increase the drive’s endurance. Speaking of endurance, SanDisk rates all of the drives at 80 TBW (terabytes written) with a 2M hour MTBF.

SanDisk Extreme II Mobile (left) and Desktop (right) Bundles

SanDisk is going to be offering a couple of different configurations of their Extreme II drives at retail, with bundles that target different users. The drives included in the kits are identical, but there will be versions offered for notebook and desktop users. The notebook kits come bundled with a 7mm to 9.5mm shim, while the desktop bundle includes a 2.5” to 3.5” mounting bracket, screws, and a SATA cable.

Test Setup, IOMeter 1.1 RC

Our Test Methodologies: Under each test condition, the Solid State Drives tested here were installed as secondary volumes in our testbed, with a standard spinning hard disk for the OS and benchmark installations. Out testbed's motherboard was updated with the latest BIOS available as of press time and AHCI (or RAID) mode was enabled. The SSDs were secure erased prior to testing, and left blank without partitions for some tests, while others required them to be partitioned and formatted, as is the case with our ATTO, PCMark 7, and CrystalDiskMark benchmark tests. Windows firewall, automatic updates and screen savers were all disabled before testing. In all test runs, we rebooted the system, ensured all temp and prefetch data was purged, and waited several minutes for drive activity to settle and for the system to reach an idle state before invoking a test.

HotHardware Test System
Intel Core i7 and SSD Powered

Processor -

Motherboard -

Video Card -

Memory -

Audio -

Hard Drives -


Hardware Used:
Intel Core i7-2600K

Asus P8Z6-V Pro
(Z68 Chipset, AHCI Enabled)

NVIDIA GeForce GTX 285

4GB Kingston DDR3-1600

Integrated on board

WD Raptor 150GB (OS Drive)
Samsung SSD 830 (256GB)
OCZ Vertex 3 (200GB)
Corsair Force GT (240GB)
Crucial M4 (256GB)
Corsair Neutron (240GB)
Intel SSD 520 (240GB)
OCZ Vertex 4 (256GB)
SanDisk Extreme II (120, 240, 480GB)

OS -
Chipset Drivers -
DirectX -

Video Drivers

Relevant Software:
Windows 7 Ultimate SP1 x64
Intel, iRST 10.5.1027
DirectX 11

NVIDIA GeForce 275.33

Benchmarks Used:
IOMeter 1.1.0 RC
HD Tune v4.61
ATTO v2.47
CrystalDiskMark v3.01 x64
PCMark 7
SiSoftware Sandra 2012

I/O Subsystem Measurement Tool

As we've noted in previous SSD articles, though IOMeter is clearly a well-respected industry standard drive benchmark, we're not completely comfortable with it for testing SSDs. The fact of the matter is, though our actual results with IOMeter appear to scale properly, it is debatable whether or not certain access patterns, as they are presented to and measured on an SSD, actually provide a valid example of real-world performance for the average end user. That said, we do think IOMeter is a reliable gauge for relative available throughput within a given storage solution. In addition there are certain higher-end workloads you can place on a drive with IOMeter, that you an't with most other storage benchmark tools available currently.

In the following tables, we're showing two sets of access patterns; our custom Workstation pattern, with an 8K transfer size, 80% reads (20% writes) and 80% random (20% sequential) access and IOMeter's default access pattern of 2K transfers, 67% reads (34% writes) and 100% random access.

These SanDisk drives are tuned for consumer-class workloads, which shows in these IOMeter tests. The three Extreme II drives we tested trailed the rest of the pack in term of total IOPS, at all queue depths, with the sample patterns we used.

As you can probably guess after having looked at the two other charts above, transfer speeds with SanDisk's Extreme II SSDs  with the IOMeter test patterns we used also trailed the other drives.

SANDRA and ATTO Disk Benchmark

Next we ran SiSoft SANDRA, the the System ANalyzer, Diagnostic and Reporting Assistant. Here, we used the Physical Disk test suite and provided the results from our comparison SSDs. The benchmarks were run without formatting and read and write performance metrics are detailed below.

SiSoft SANDRA 2012
Synthetic HDD Benchmarking

All three of the SanDisk Extreme II drives we tested put up some excellent scores in the Read portion of this benchmark, which positioned all of the drive at (or near) the top of the chart. Write bandwidth was also very good for the 240GB and 480GB drives. The 120GB drive can't offer the same kind of write bandwidth as the higher capacity drives, but it still performed very well.

ATTO Disk Benchmark
More Information Here: http://bit.ly/btuV6w

ATTO is another "quick and dirty" type of disk benchmark that measures transfer speeds across a specific volume length. It measures raw transfer rates for both reads and writes and graphs them out in an easily interpreted chart. We chose .5kb through 8192kb transfer sizes and a queue depth of 6 over a total max volume length of 256MB. ATTO's workloads are sequential in nature and measure raw bandwidth, rather than I/O response time, access latency, etc.

The three SanDisk Extreme II drives we tested once again posted some excellent scores. The 240GB and 480GB Extreme II drives consistently performed alongside some of the fastest drives we've tested, in both the Read and Write portions of the benchmark. The 120GB drive also put up some nice scores in the Read test, but its write performance fell somewhere in the middle of the pack.

HD Tune Benchmarks
EFD Software's HD Tune is described on the company's web site as such: "HD Tune is a hard disk utility with many functions. It can be used to measure the drive's performance, scan for errors, check the health status (S.M.A.R.T.), securely erase all data and much more." The latest version of the benchmark added temperature statistics and improved support for SSDs, among a few other updates and fixes.

HD Tune v4.61
More Info Here: http://www.hdtune.com

The SanDisk Extreme II drives led the pack in terms of average transfer rate according to the HD Tune benchmark. Access times for the three SanDisk drives were middling, however, and burst rates trailed the competition.

CrystalDiskMark Benchmarks

CrystalDiskMark is a synthetic benchmark that tests both sequential and random small and mid-sized file transfers using incompressible data. It provides a quick look at best and worst case scenarios with regard to SSD performance, best case being larger sequential transfers and worse case being small, random transfers.

CrystalDiskMark Benchmarks
Synthetic File Transfer Tests

The SanDisk Extreme II SSDs we tested performed very well in the various CrystalDiskMark tests. The SanDisk drives led the pack in the sequential transfer test, but finished at the bottom in the 512K transfer test. With 4K transfers at the lower queue depth, the SanDisk drives fell somewhere in the middle of the pack, but they came roaring back in the 4K QD32 transfer test and offered some of the best performance once again.

AS-SSD Compression Test

Next up we ran the Compression Benchmark built-into AS SSD, an SSD specific benchmark being developed by Alex Intelligent Software. This test is interesting because it uses a mix of compressible and incompressible data and outputs both Read and Write throughput of the drive. We only graphed a small fraction of the data (1% compressible, 50% compressible, and 100% compressible), but the trend is representative of the benchmark’s complete results.

AS SSD Compression Benchmark
Bring Your Translator: http://bit.ly/aRx11n

The compressibility of the data being transferred on the SanDisk Extreme II drive has no measurable impact on performance. In both the Read and Write tests, all three of the SanDisk Extreme II drives we tested offered flat, consistent performance. As we've seen in a few of the other tests, the 240GB and 480GB Extreme II drives put up read and write scores among the best drives here, but the 120GB model can't offer quite the same write performance.

PCMark 7 Storage Benchmarks
We really like PCMark 7's Secondary Storage benchmark module for its pseudo real-world application measurement approach to testing. PCMark 7 offers a trace-based measurement of system response times under various scripted workloads of traditional client / desktop system operation. From simple application start-up performance, to data streaming from a drive in a game engine, and video editing with Windows Movie Maker, we feel more comfortable that these tests reasonably illustrate the performance profile of SSDs in an end-user / consumer PC usage model, more so than a purely synthetic transfer test.

Futuremark's PCMark 7 Secondary Storage

The three SanDisk Extreme II drives we tested were among the best performers according to PCMark 7. The AData SX900 put up the best overall score, mostly because it put up the highest scores (by very small amounts) in 5 of the 7 individual PCMark 7 storage benchmark tests. The Extreme II 480GB drive was very close behind though, with the 240GB right alongside.

Our Summary and Conclusion

Performance Summary: SanDisk’s Extreme II series of solid state drives generally performed very well throughout our entire battery of tests. They faltered a bit in our IOMeter tests, but consistently offered some of the best read performance we have seen to date, with competitive write performance as well. The drives excelled with large sequential transfers, and with small random transfers at higher queue depths. Performance with SanDisk’s Extreme II drives is consistent regardless of the compressibility of the data being used and access times were competitive as well.

The SanDisk Extreme II SSD

As we’ve mentioned, SanDisk will initially be offering three drives in the Extreme II series of products with 120GB, 240GB and 480GB capacities. Pricing for the drives is set at $129.99 (120GB), $229.99 ($240GB), and $439.99 (480GB). At those prices, the SanDisk Extreme II series of drives are slight more expensive than competing offerings, but we suspect street prices to tip-toe downward as availability ramps up. Considering the consistently high performance of the drives though, pricing is still competitive.

Ultimately, we think SanDisk’s new Extreme II series of solid state drives are top-notch and worthy of consideration for your next build / upgrade. Overall performance is very good, the drives offer high endurance and they’re backed by a 5-year warranty from a company that’s been around for ages. If you’re looking for a high-performance SSD, SanDisk’s Extreme II SSDs should be on your short list.

  • Solid Performance
  • Multi-Tiered Cache
  • Consistent Performance, Regardless of Data Type
  • Prices Slightly Higher Then Some Competing Drives

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