Intel 520 SSD 240GB review

Intel's new 520 series SSD is the fastest you'll see outside of a data centre.
Photo of Intel 520 SSD 240GB

Intel’s latest SSD (Solid State Drive) model 520 feels rather familiar as it sports the same light silver casing as the model 510 and 1ooks pretty similar to every Intel SSD since the first X25-M which was launched back in 2008. 

The retail package of goodies is also familiar and consists of a SATA cable, a power adapter, a small bag of screws and a 3.5in to 2.5in drive bay adapter. The drive measures 6.5mm thick with a spacer that takes it up to 9mm so you’ll have no problem installing the drive in either a laptop or desktop PC. You can download what Intel calls Data Migration Software, which is actually a Lite version of Acronis True Image Home 2010. 

That 520 name isn’t especially illuminating so here’s our ready reckoner of Intel SSD model codes. 3xx is mainstream/corporate IT with SATA II interface, 5xx is performance/enthusiast with SATA III and 7xx is reserved for the data centre.

Intel SSD 520 inside 2

All hail SandForce

Things take a turn for the interesting when we peek at the specification for the new drive. As you would expect the 520 sports a SATA III/6Gbps interface. There are five models in the range (60GB, 120GB, 180GB, 240GB and 480GB) and all five have a claimed sequential read speed of 550MB/sec, which is significantly higher than the 450MB/sec of the 510 SSD. 

Claimed write speeds are a little more complicated with 475MB/sec for the baby 60GB model, 500MB/sec for the 120GB version and 520MB/sec for 180GB, 240GB and 480GB models, where the 510 SSD achieved a mere 210MB/sec.

The smaller models have lower performance because they use fewer flash memory chips to achieve the desired capacity and this limits the number of memory channels. Our 240GB sample is fully populated with 16 memory chips (eight on each side of the PCB) so we speculate that the 60GB model has four chips and the 120GB has eight chips.

The memory chips use 25nm Intel MLC flash technology, however the explanation for the huge leap in performance lies squarely with the SSD controller which is a SandForce 2281. Intel uses its own controller in the 3xx SSD and opted for a Marvell chip in the 510, so the shift to SandForce for 520 suggests that Intel is perfectly happy to choose the best piece of silicon for a particular job.

Intel tells us that it “… worked with SandForce to customise its firmware. It then went through substantial testing, making many changes to create an Intel-unique firmware that will result in a product that is more reliable and higher performing than other SSDs based on a similar SandForce controller.” That’s a bold claim but Intel clearly has confidence in the 520 as it provides a five-year limited warranty.


Key features

Intel details two features of the 520 that look interesting at first glance. The first is support for AES 256-bit encryption – we wondered whether this was connected with Intel AVX and the latest version of SSE4.2 which is supported by Intel Sandy Bridge processors. But no, this encryption feature is handled by the SandForce chip and is therefore available to every SSD manufacturer and is not specific to the Intel 520.

We were also intrigued by the Data Compression Engine, which compresses data to free up storage space. The amount of compression depends on the type of data on your drive so it’s all rather vague but we do have some numbers. The Iometer benchmark prepares a drive by filling it with a single enormous file. During testing the 223GB (formatted) drive was completely full but a few hours later it had magically gained 16GB of free space, presumably thanks to thecompression algorithm.

The problem that Intel faces is that the 520 is pretty much identical to any SandForce SSD that uses Intel memory such as the Kingston HyperX. The bundle in the package is run of the mill so the two variables are the firmware (and hence the performance) and pricing. Kingston prices its 240GB HyperX at £300 which seems expensive however the 240GB OCZ Vertex 3 costs £370 so this £400 Intel 520 is in the same league as the Vertex 3.

Testing and performance

We tested the Intel 520 on a system with a Core i7-3960X processor, Foxconn Quantumian-1 motherboard, 16GB of G.Skill RipJawsZ DDR3 RAM running on 64-bit Windows 7 Pro. We used the native Intel SATA III/6Gbps interface and were blown away by the performance. The Marvell chipped Intel 510 was no slouch, but it finds itself effectively destroyed by the SandForce drives in Iometer and CrystalDiskMark. 

It is harder to separate the Kingston HyperX and Intel 520 as Intel rules the roost in our Iometer Read test, honours are even in the Iometer Write test and CrystalDiskMark, and Kingston wins in HD Tach. Those differences must surely lie in the two companies’ approach to the firmware on their respective drives. 

When we ran a real world test and copied a 2GB folder of files within each drive we couldn’t separate the Intel 510 from the 520 or Kingston HyperX.

Intel 520 240GB HDTach

Kingston HyperX 240GB HD Tach

Intel 510 120GB HDTach

Company: Intel


Contact: 01793-403000

  • Superb performance, five-year warranty.
  • The price is rather high.


SandForce is a superb SSD controller and the Intel 520 is a formidable new entrant to the performance PC/laptop arena. We love every aspect of this drive with one notable exception and that is the horribly high price.