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SanDisk Extreme II review: High speed at low cost

SanDisk's new high-end Extreme II SSD is fast while costing about the same as a budget SSD.

Dong Ngo SF Labs Manager, Editor / Reviews
CNET editor Dong Ngo has been involved with technology since 2000, starting with testing gadgets and writing code for CNET Labs' benchmarks. He now manages CNET San Francisco Labs, reviews 3D printers, networking/storage devices, and also writes about other topics from online security to new gadgets and how technology impacts the life of people around the world.
Dong Ngo
6 min read

The SanDisk Extreme II solid-state drive (SSD) has a lot more going for it than just being 2.5mm thinner than the previous SanDisk Extreme.


SanDisk Extreme II

The Good

The <b>SanDisk Extreme II</b> offers faster performance, is now available in a 7mm design, and has a friendly price tag.

The Bad

There's no desktop drive bay converter or other accessories included.

The Bottom Line

The SanDisk Extreme II is a speedy replacement for any hard drive, and it won't dig a big hole in your wallet.

In my testing, the new and trim SSD offered fast performance, comparable to that of even the fastest consumer-grade SSDs, while costing well less than $1 per gigabyte. The drive can work with both laptops and desktops, but unfortunately, doesn't come included with a drive bay converter to fit easily in a desktop, which is its only shortcoming, and a minor one.

The Extreme II definitely is an easy recommendation to those looking to upgrade their computer's existing hard drive to a much faster alternative. It currently costs just $230 for 240GB (or $450 for 480GB) with street pricing expected to fall even lower once the drive has been on the market for awhile. For more choices of excellent SSDs, check out the drives on this list.

The Extreme II SSD next to its predecessor, the Extreme SSD.
The Extreme II SSD next to its predecessor, the Extreme SSD. Dong Ngo/CNET

Capacties 120GB, 240GB, 480GB
Current pricing $140, $230, and $450, respectively.
Controller Marvell 88SS9187 (Monet)
NAND SanDisk 19nm eX2 ABL MLC NAND
Standards 7mm 2.5-inch design, SATA 3, SATA 2, SATA
Sequential Read Up to 550MBps
Sequential Write UP to 500MBps
4KB Random Read Up to 95K IOPS
4KB Random Write Up to 78 IOPS
Endurance 80TB Written
Warranty Five years
OS supported Windows, Mac, Linux

Standard design, advanced configuration, and friendly pricing
At first glance, the Extreme II looks almost identical to the Extreme, both with black cover and a big SanDisk logo in red. Looking closer, however, the new drive is just 7mm thick, similar to most new SSDs, and downright trim compared to the 9.5mm girth of the previous model.

The new thickness means it can now work in certain ultrabooks, in addition to desktops and standard laptops. This is not the thinnest SSD on the market, however, since the Seagate 600 SSD comes in a version that's just 5mm thick.

On the inside, the new Extreme II is now totally different than its predecessor. The drive uses the Marvell 88SS9187 Monet controller (as opposed to the SanForce controller of the original Extreme drive) and SanDisk 19nm eX2 ABL MLC NAND flash memory. Not only that, the new Extreme II also use nCache, which was first introduced in the SanDisk Ultra Plus. All of these improvements translate into the random performance ratings being more than twice those of the the Extreme.

Beyond those specs, the SanDisk Extreme II is a standard SATA internal drive that supports SATA 3 (6Gbps) and works with all revisions of the SATA standard. The drive is the first high-end SSD I've seen that's priced less than $1 per gigabyte at release, currently costing $230 and $450 for the 240GB and 480GB, respectively. The 120GB is slightly more expensive at $140. Like most SSDs, the price of the Extreme II likely gets lower the longer it's on the market.

Internal hard drives' cost per GB
(Shorter bars indicate better performance, Measured in dollars, based on current street pricing)
Cost per GB  
SanDisk Extreme II (480GB)
SanDisk Extreme II (240GB)

Note that, unlike some other SSDs that include a 3.5-inch drive bay converter that helps fit the drive into a desktop, the Extreme II doesn't. This is not a big deal, however, since you can always get a third-party caddy or you might even leave the drive hanging loose inside a desktop's chassis. Since there's no moving parts, an SSD doesn't need to be securely attached to a computer that's not moved around often.

High endurance and top warranty
As all SSDs go, the new Extreme II has finite endurance, called program cycles (read more about them here), meaning you can write only so much data to it before it becomes unreliable. However, the drive has a high endurance rating of 80TB over its lifetime. This means if you write 50GB to the drive every day, it will take about 4.5 years for the drive to run out of program cycles. Most of us don't write more than 10GB to the computer's internal drive per day, and there are many days that we don't write much to the drive at all.

To back up this high-endurance claim, SanDisk includes with the Extreme II its top five-year warranty, which is longer than that of most SSDs on the market.

Formidable performer

The Extreme II performed very well in my testing. It was the first SSD that was tested with both CNET's real-world test and the PCMark 8 benchmark suite, and I stacked it against only the current high-end drives on the market.

In real-world tests, the drive was used both as a secondary drive and the main drive that host the operating system. When used as a secondary drive, it offers the sequential real-world sustained write speed of 256MBps and the read speed of 203MBps. Both on bar with the rest of the high-end SSDs.

When used as the main drive do performed a mixture of both sequential and random performance, both reading and writing, at the same time, it offered 224MBps, which was very fast. Note that generally, SSDs are designed to work well in a mixed or random access-oriented environment rather than just extensive sequential write or read, such as data copying.

CNET Labs' Data transfer speeds
(Measured in MB per second; longer bars indicate better performance)
As secondary drive (read only)  
As secondary drive (write only)  
As OS drive (read and write)  
OCZ Vector
Plextor M5 Pro Xtreme
SanDisk Extreme II
Seagate 600 SSD
Transcend SSD720
Seagate Laptop Thin SSHD

The drive also cut the system's boot and shutdown times significantly compared to when the system used a hard drive as its main storage. The system also resumed from sleep mode instantly.

CNET Labs' Boot time/Shutdown time
(Measured in seconds, shorter bars indicate better performance)
Shutdown time  
Boot time  
OCZ Vector
SanDisk Extreme II

PCMark benchmark software delivered testing scores with high numbers meaning better performance. The benchmark suite provide multiple tests including Home, Work and Storage. The Home and Work tests measure the system performance when doing tasks tailored for those types of usage, respectively. In these tests, the internal drive plays just a small role. On the other hand, the Storage test focuses mainly on the internal drive itself.

The Extreme II's scores in all of these test were on a par with those of other high-end SSDs, and its Storage score was higher than the average.

PCMark 8 Scores
(Longer bars indicate better performance)
Storage score  
Work score  
Home score  
OCZ Vector
Plextor M5 Pro Xtreme
SanDisk Extreme II
Seagate 600 SSD
Transcend SSD720
Seagate Laptop Thin SSHD

In all, I was impressed with the Extreme II's performance, especially considering how much it costs. Note that since SSDs are much faster than regular hard drives, it's generally hard to detect differences between them in terms of performance. For this reason, the friendly pricing of the Extreme II makes it that much of a better deal.

While not the fastest, the Extreme II is a very fast SSD, and most importantly, it's far from being the most expensive drive on the market. In fact, it's one of the most affordable, especially the 240GB and 480GB capacities. SanDisk did a good job with this new SSD by bringing high performance to a price point that many consumers can afford.


SanDisk Extreme II

Score Breakdown

Setup 8Features 8Performance 8Support 9