Intel 520 Series 120GB SandForce SSD

Table of Contents

The 520 Series 120GB takes the ubiquitous LSI SandForce SF-2281 SSD controller and pairs it with Intel’s vast manufacturing and engineering resources. It’s backed by a lengthy 5-year warranty and Intel’s reputation for reliability.

September 24, 2012 by Lawrence Lee

Intel 520 Series 120GB
2.5″ SSD (OEM model)
Street Price

When consumer SSDs began to pick up steam about four years ago, there weren’t a lot of solid choices available. Manufacturers were jumping into the space left and right to get in on the next big thing, the technology that would do away with mechanical hard drives. Early adopters suffered the growing pains of this emerging market, with many spending substantial amounts of cash on what turned out to be lemons. Problems like crashing, bricking, and performance drops weren’t uncommon.

Then chip giant Intel decided to enter the game using their own controller, firmware, NAND Flash chips, and the enormous resources at their disposal to develop the X25 series, which quickly established itself as the benchmark for both performance and stability. Though the state of SSDs is now greatly improved, there are still those who remain unconvinced that all the kinks of this relatively new technology have been worked out. After all, even the most popular controller today, the SandForce SF-2281, began its run with a notorious widespread BSOD bug affecting many of the numerous SSDs that utilized it.

Lacking a 6 Gbps controller, Intel also got on the SF-2281 SandForce bandwagon, but not before putting it through a rigorous testing period of more than a year before taking it to market. The culmination of this effort was the Intel 330 and 520 Series. Despite all this work, on paper there is little to differentiate itself from the hordes of SF-2881 equipped drives from their competitors. The only thing notable in its specifications is its 5 year warranty.

Intel 520 Series 120GB: Specifications
(from the manufacturer web site)
Components Intel
Capacity 120 GB
Form Factor 2.5 inch SATA
Interface SATA – 6.0 Gb/s
Lithography 25nm
Sequential Write 500 MB/s
Random Read (8GB Span) 25000 IOPS
Random Write (8GB Span) 40000 IOPS
Latency – Read 80 µs
Latency – Write 85 µs
Power – Active 850 mW (MobileMark 2007 Workload)
Power – Idle 600 mW (DIPM)
Vibration – Operating 2.17 GRMS (5-700 Hz)
Vibration – Non-Operating Vibration – Non-Operating 3.13 GRMS (5-800 Hz)
Shock (Operating and Non-Operating) 1,5000 G/.5 msec
Operating Temperature 0 – 70 C
Weight Up to 78 grams
Mean Time Between Failures (MTBF) 1,200,000 Hours
Uncorrectable Bit Error Rate (UBER) 1 sector per 1016
Warranty Period 5 yrs


Intel Consumer SSD Comparison
320 Series
330 Series
520 Series
Interface SATA 3Gb/s SATA 6Gb/s SATA 6Gb/s
Sequential Performance (read/write) 270 / 220 MB/s 500 / 450 MB/s 550 / 520 MB/s
Random Performance (4KB read/write) 39.5k / 23k IOPS 42k / 52k IOPS 50k / 80k IOPS
Capacities (GB) 40 / 80 / 120 / 160 / 300 / 600 60 / 120 / 180 / 240 60 / 120 / 180 / 240 / 480
Warranty 5-year limited 3-year limited 5-year limited

The main difference between the 520 and 330, aside from a warranty length, is that the 330 is equipped with lower endurance NAND Flash (similar to the difference between the Kingston HyperX and HyperX 3K), pushing it down one rung down the ladder. This doesn’t explain the performance discrepancies in the spec sheet, however, suggesting that the chips used are actually slower. As Intel produces their own 25nm synchronous NAND Flash for both models, it wouldn’t be surprising to learn that they have binned the faster chips in addition to the more durable ones and reserved them for the 520 series. The 320 series is unrelated, using the last revision of Intel’s 3 Gb/s controller, an evolution of the X25.

Box and contents (OEM version).

The drive.

Our sample is an OEM model shipping in a plain, foam-lined cardboard box with nothing but the drive in an antistatic bag and Intel sticker. Two of these were acquired for use in an upgrade of theSPCR web server.

The retail version includes a 3.5 inch adapter as well as a SATA data cable and power adapter. Physically, the drive itself is similar to some incarnations of the X25 G2 line, outfitted with a standard 9.5 mm metallic casing with a black border running around the rim on the top. This frame can be removed, effectively making the 520 a 7 mm thick drive suitable for ultrabooks that require the slightly slimmer form factor.


Our samples were tested according to our standard
hard drive testing methodology
. As of mid-2008, we have been conducting most acoustics tests in our own 10~11 dBA anechoic chamber, which results in more accurate, lower SPL readings than before, especially with <20 dBA@1m SPL.

Two forms of hard drive noise are measured:

  1. Airborne acoustics
  2. Vibration-induced noise.

These two types of noise impact the subjective
perception of hard drive noise differently depending on how and where the drive
is mounted.

Both forms of noise are evaluated objectively and
subjectively. Airborne acoustics are measured in our anechoic chamber using a lab reference
microphone and computer audio measurement system
. Measurements are taken at a distance of one meter from the top
of the drive using an A-weighted filter. Vibration noise is rated on a scale
of 1-10 by comparing against our standard reference drives.

As of late-2011, we have been conducting performance testing. A combination of timed real-world tests is used to represent a workload of common activities for a boot drive including loading games, running disk-intensive applications, copying files, and installing programs. Synthetic tests are also run to better judge the performance across the entire span of the drive.

Summary of primary HDD testing tools:

Key Components in LGA1155 Heatsink Test Platform:

Performance Test Tools:

Benchmark Details

  • Boot: Time elapsed between pressing the power button to the desktop and the Windows start sound playing (minus the average time to get to the “loading Windows” screen, 11 seconds on our test system)
  • COD5: Combined load time for “Breaking Point” and “Black Cats” levels.
  • Far Cry 2: Load time for one level.
  • ExactFile: Creating a MD5 check file of our entire test suite folder.
  • TrueCrypt: Creating a 10GB encrypted file container.
  • 3DMark Vantage: Install time, longest interval between prompts.
  • PowerDVD 10: Install time, longest interval between prompts.
  • Small File Copy: Copy time for a variety of small HTML, JPEG, MP3, ZIP, and EXE files.
  • Large File Copy: Copy time for 4 AVI files, 2 x 700MB and 2 x 1400MB
    in size.

A final caveat: As with most reviews, our comments
are relevant to the samples we tested. Your sample may not be identical. There
are always some sample variances, and manufacturers also make changes without
telling everyone.

Ambient conditions at time of testing were 10.5 dBA and 22°C.


A Windows 7 image loaded with our test suite was cloned to a 50GB partition
at the beginning of each drive after a complete format. Our entire
test suite was run start to finish three times with a defragmentation (SSDs and hybrid drives excluded) and reboot
between runs.
Average times were collected for comparison.

The Intel 520 exhibited subpar performance in our loading tests. Though it had one of the fastest boot-up times, it lagged behind most of the other SSDs in our game tests.

In our application tests the Intel 520 delivered middling time results thanks to a slight slowdown in our TrueCrypt test, suggesting the drive’s write performance isn’t quite up to snuff.

The Intel 520 put on a better show in our file copy tests, being a bit slow with large files but incredibly quick with small ones.

Lackluster results were attained in our installation tests. The 520 took about four seconds longer to install PowerDVD than most of the tougher competition.

To accurately represent the overall results of our real world performance tests, we gave each model a proportional score in each benchmark series (loading, application, file copy, and installation) with each benchmark set equally weighted. The scale has been adjusted so that among the drives compared, a perfectly average model scores 100 points.

The Intel 520 120GB scored 108.1 points on our scale, eking out a win over the ADATA SX910 128GB. Compared to other SandForce SSDs, it isn’t particularly impressive performance-wise, but the the difference is quite small and difficult to notice in real life situations.


Though our timed benchmark tests do a fair job of simulating performance in real world situations, they don’t tell the whole story. Synthetic tests like HD Tune and CrystalDiskMark help fill the gap. Note: On SSDs, a full format was conducted before running these tests.

HD Tune’s main benchmark shows the 520 taking a substantial hit in write sequential write speed compared to most of our recently tested SSDs, even the other SF-2281 models. Access times were okay at about 0.20 ms.

In CrystalDiskMark, using a block size of 512K and a random data set, the 520 displayed very strong sequential and random read speeds but its write performance was underwhelming. Random read/write figures using the smaller 4K block size were far less impressive.

Switching to an easily compressible data set (0x00 fill) resulted in huge performance gains which is typical for SandForce drives as they use compression to limit the number of writes and increase speed. The 520 is much more competitive under these conditions, trailing only slightly behind in 512K performance. With 4K blocks, the 520 was formidable in read/writes with a queue depth of 32, the type of access pattern associated with servers where multiple simultaneous data requests pile up.


The energy efficiency of the Intel 520 Series 120GB was poor compared to other SSDs. Its power consumption was more typical of a 5400 RPM notebook hard drive. As a notebook upgrade, don’t expect any battery life improvement.


As solid state drives have no spinning platters or moving parts of any kind, they are effectively silent storage devices. It is possible that there could be a tiny bit of electronic noise (typically a high pitched squeal) being emitted, either intermittently depending on task, or continuously, but the Intel 520 Series 120GB was completely silent. The only SSD we’ve ever tested that made any audible noise was a Zalman S Series 128GB sample that produced an odd high frequency squeal whenever it was accessed.


In our real world performance tests, the Intel 520 Series 120GB had mixed results compared to other SandForce models, squeaking past the ADATA SX910 128GB but not quite able to catch the Corsair Force GS 240GB nor the Kingston HyperX 3K 240GB and Samsung 830 Series 128GB. Its lackluster numbers weren’t buoyed by synthetics tests, either; its speed in both HD Tune and CrystalDiskMark weren’t terribly impressive. The 520 also failed to demonstrate superiority in energy efficiency, with power consumption figures comparable to its SandForce comrades.

What really differentiates this seemingly run-of-the-mill SSD is the Intel name and all it stands for. Like all of Intel’s products, the 520 has undergone an extensive validation process. Intel worked on developing SandForce drives for well over a year before release and they’ve also backed the 520 with an industry leading 5 year warranty. Though the days of unreliable SSDs are mostly behind us, having an Intel drive still instills a sense of confidence in many. The stability of the drive is of course impossible to confirm without a fleet a drives and long-term stress tests, so it’s really a complete intangible. [Editor’s Note: These are the reasons we chose the 520s for our web server… but most readers here know that Intel is hardly infallible, either: Remember the assive Intel P67 and H67 chipsets moderboard recall at their launch?]

Aside from this “X” factor and the fact that the black metal frame can be removed to make it a 7 mm thick drive, the Intel 520 Series 120GB is fairly unremarkable. It doesn’t excel or falter in any particular area and its street price of US$120 is not especially affordable either by today’s standards. We can’t say with confidence that it’s worth the slight premium over cheaper models that often dip to US$100 or below with mail-in rebates, etc. but we have a feeling even if you’re not delighted with the price, you won’t end up regretting the purchase.

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SPCR Articles of Related Interest:

Crucial M4 64GB: Solid-State on a Budget
Kingston HyperX 3K 240GB vs. Samsung 830 Series 128GB
Corsair Force GS 240GB: SandForce with Toggle-Mode NAND
Western Digital Red 3TB & 1TB Hard Drives
ADATA XPG SX910 128GB Solid State Drive
WD VelociRaptor 1TB and Scorpio Blue 500GB

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