[nextpage title=”Introduction”]
Solid state drives have come down significantly in price over the last few years, so it’s now cheaper than ever to upgrade your PC. While 128 GiB units offer the best compromise between price and capacity in most cases, some users may opt for a 256 GiB model instead if extra storage space is required. Today we are going to look at two of the latest 256 GiB models; the Corsair Neutron and the OCZ Agility 4.
There are many components in a PC that can be upgraded to make it faster, but none are as noticeable in the real world as upgrading a hard drive to a solid state drive. A 256 GiB solid state drive is ideal for those who are confined to a single drive in a laptop or those who need a lot of storage space for large applications and games.
Even though both units have 256 GiB of memory inside, the Corsair Neutron is sold as a 240 GiB, since 16 GiB is reserved for overprovisioning, used by the garbage collection and wear leveling mechanisms of the unit.
Figure 1: The two SSDs on test
Before proceeding, we highly suggest that you read our “Anatomy of SSD Units” tutorial, which provides all the background information you need to know about SSDs. Both of the SSDs featured in this review use MLC memory chips.
In the table below we are comparing the Corsair Neutron 240 GiB with the OCZ Agility 4 256 GiB. Both units use a SATA-600 interface and occupy a 2.5” form factor.
| Manufacturer | Model | Model # | Nominal Capacity | Price |
| Corsair | Neutron | CSSD-N240GB3-BK | 240 GiB | USD 210 |
| OCZ | Agility 4 | AGT4-25SAT3-256G | 256 GiB | USD 150 |
We researched the prices on the day that we published this review. In the table below, we provide a more in-depth technical comparison between the two drives. Most chip manufacturers don’t detail the specifics of their chips on their websites, so we are only linking to what we found.
| Model | Controller | Buffer | Memory |
| Corsair Neutron | Link_A_Media LM87800 | 2x 128 MiB K4T1G08QF | 16x 16 GiB Micron 29F128G08CFAAB |
| OCZ Agility 4 | Indilinx Everest 2 IDX400M00-B0 | 2x 256 MiB Hynix H5TQ2G63BFR | 16x 16 GiB OCZ H2502128T048AX22 |
[nextpage title=”The Corsair Neutron 240 GB”]
The Corsair Neutron features a metal casing which should do a good job of protecting the internal components for damage. There are warranty seals in place to prevent you from tampering with the insides.
Figure 2: The Corsair Neutron 240 GB
On the top side of the PCB there are eight 16 GiB Micron 29F128G08CFAAB memory chips, alongside a single 128 MiB K4T1G08QF cache chip.
Figure 3: The Corsair Neutron 240 GB PCB
Turning the PCB over, you can see the Link-A Media LM87800 controller and the other eight 16 GiB memory chips and a further 128 MiB cache chip.
Figure 4: The Corsair Neutron 240 GB PCB (underside)
[nextpage title=”The OCZ Agility 4 256 GB”]
The OCZ Agility 4 features a plastic and metal casing which is lightweight and rigid. It looks attractive and should do a good job of protecting the internal components.
Figure 5: The OCZ Agility 4
The top side of the PCB features the Indilinx Everest 2 controller, alongside eight 16 GiB OCZ-branded H2502128T048AX22 memory chips. There is also a single 256 MiB Hynix cache chip on this side.
Figure 6: The OCZ Agility 4 PCB
Turning the PCB over reveals eight further 16 GiB memory chips alongside a further cache trip. The overall storage capacity of 256 GiB is reduced to around 238 GiB when formatted in Windows.
Figure 7: The OCZ Agility 4 PCB (underside)
[nextpage title=”How We Tested”]
During our testing procedures, we used the configuration listed below. The only variable component between each benchmarking session was the SSD being tested.
Hardware Configuration
- CPU: Intel Core i7-3930K
- Motherboard: ASUS P9X79
- Memory: Four 4 GB Mushkin Blackline modules
- Video Card: AMD Radeon HD 7950 3 GB
- Video Resolution: 1920 x 1080
- Video Monitor: Viewsonic VX2260WM
- Power Supply: SilverStone 1,000 W
- CPU Cooler: NZXT Kraken X40
- Boot Drive: Kingston HyperX 3K 240 GB
Software Configuration
- Operating System: Windows 7 Home Premium 64-bit using NTFS File System
- Intel INF Driver Version 9.2.0.1016
- AMD Driver Version: AMD Catalyst 12.3
Benchmarking Software
Error Margin
We adopted a 3% error margin in our tests, meaning performance differences of less than 3% can’t be considered meaningful. Therefore, when the performance difference between two products is less than 3%, we consider them to have similar performance.
[nextpage title=”Compressible Data Test”]
As you will have gathered from the previous page, we measured the performance of each drive using two different programs: CrystalDiskMark and Iometer.
It’s important to note that we connected the SSDs to a SATA-600 port on our motherboard rather than a SATA-300 port, which could cause performance limitations.
We set CrystalDiskMark to “All 0x00 Fill mode” to evaluate the performance of the SSD when dealing with compressible data.
In the sequential read test, the Corsair Neutron achieved 22 percent better performance than the OCZ Agility 4. However, in the sequential write test, the OCZ Agility 4 performed the best, beating the Corsair Neutron by 11 percent.
Moving on to the random read test using 512 kB blocks, the Corsair Neutron offered the best performance, beating the OCZ Agility 4 by 81%. However, in the random write test using 512 kB blocks, the OCZ Agility 4 beat the Corsair Neutron by 11%.
In the random read test using 4 kB blocks, the Corsair Neutron beat the OCZ Agility 4 by 25 percent. However, in the random write test using 4 kB blocks, the OCZ Agility 4 beat the Corsair Neutron by a margin of 56 percent.
[nextpage title=”Incompressible Data Test”]
For this test, we set CrystalDiskMark to the default mode, which uses incompressible data.
In the sequential read test, the Corsair Neutron outperformed the OCZ Agility 4 by a margin of 22 percent. However, in the sequential write test, the OCZ Agility 4 outperformed the Corsair Neutron by a margin of 11 percent.
Moving on to the random read test using 512 kB blocks, the Corsair Neutron outperformed the OCZ Agility 4 by a margin of 82 percent. However, the OCZ Agility 4 came out on top in the random write test using 512 kB blocks, beating the Corsair Neutron by a margin of 12 percent.
In the random read test using 4 kB blocks, the Corsair Neutron performed best, achieving 24% higher performance than the OCZ Agility 4. However, in the random write test using 4 kB blocks, the OCZ Agility 4 outperformed the Corsair Neutron by 53 percent.
[nextpage title=”Iometer”]
Iometer is an open-source benchmark which lets us synthetically test the input and output operations per second of a storage drive. We will be looking specifically at random read and write scores using 4 kB blocks.
In the random read test using 4 kB blocks, the Corsair Neutron outperformed the OCZ Agility 4 by a small margin of 4.4 percent. The Corsair Neutron also beat the OCZ Agility 4 in the random write test using 4 kB blocks by a slightly larger margin of 14 percent.
[nextpage title=”Conclusions”]
It is quite clear from our test results that both the Corsair Neutron and OCZ Agility 4 offer impressive performance. However, it’s also clear that the two drives have their strengths and weaknesses in different areas.
The Corsair Neutron offered much higher performance than the OCZ Agility 4 throughout all of the sequential and random read tests with no exceptions.
One of the key aspects of the Corsair Neutron to note is the consistency of performance throughout the compressible and incompressible data tests. This is because the Link-A Media controller doesn’t rely on data compression to achieve high speeds.
The OCZ Agility 4 performed better throughout the write tests and, again, the results were fairly consistent through compressible and incompressible data tests. In fact, the only write test in which the OCZ Agility 4 didn’t achieve higher performance than the Corsair Neutron was in the IOPS test.
When we consider the price of the two drives, the Corsair Neutron is around USD 60 more expensive than the OCZ Agility 4.
The OCZ Agility 4 has a slightly larger capacity than the Corsair Neutron because the controller doesn’t use overprovisioning. This results in around 15 GiB more usable space when formatted in Windows. However, the Corsair offer a five-year warranty with the Neutron, compared to OCZ’s three years. This makes it a better option for those who don’t upgrade their system very often and want the peace of mind of a longer guarantee.
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