RAID is an acronym standing for– depending upon who you ask– either “Redundant Array of Independent Drives” or “Redundant Array of Inexpensive Drives”. There are many types of RAID, some designed for data redundancy and reliability; some designed for speed, and some designed for a combination of both, but the common point of all RAID systems is that read and write requests are spread across multiple drives. There are many RAID variants but the three most common are mirrored systems, where multiple drives each contain the same data, ensuring data integrity if a drive fails; parity systems use a dedicated parity drive as a running check on the data, and the system we’ll be using, a striped system that splits reads and writes across multiple drives.
Theoretically a two-drive RAID-0 setup can result in a doubling of raw read and write performance, since each drive only has to handle half the data. In the real world, a 50% increase is a more reasonable expectation. Also, note that a two-drive RAID-0 system doubles your chances of drive failure, since both drive appear as a single logical drive to your system.
RAID-0 setups used to be common on enthusiast machines, as doubling the performance of a relatively slow hard disk was a huge win. But while RAID-0 will improve data transfer speeds, it won’t do a thing for IOPS– the number of requests the storage subsystem can handle per second. This is critical since the improved IOPS performance is the main reason SSD-based systems feel faster in daily use than hard drive based systems. Since a single SSD will outperform even RAIDED hard disks in data transfer rates, and vastly outperform them in IOPS, the utility of a RAID-0 system is less apparent than it used to be.
SSD Testing Disclaimer
Early on in our SSD coverage, Benchmark Reviews published an article which detailed Solid State Drive Benchmark Performance Testing. The research and discussion that went into producing that article changed the way we now test SSD products. Our previous perceptions of this technology were lost on one particular difference: the wear leveling algorithm that makes data a moving target. Without conclusive linear bandwidth testing or some other method of total-capacity testing, our previous performance results were rough estimates at best.
Our test results were obtained after each SSD had been prepared using DISKPART or Sanitary Erase tools. As a word of caution, applications such as these offer immediate but temporary restoration of original ‘pristine’ performance levels. In our tests, we discovered that the maximum performance results (charted) would decay as subsequent tests were performed. SSDs attached to TRIM enabled Operating Systems will benefit from continuously refreshed performance, whereas older O/S’s will require a garbage collection (GC) tool to avoid ‘dirty NAND’ performance degradation.
It’s critically important to understand that no software for the Microsoft Windows platform can accurately measure SSD performance in a comparable fashion. Synthetic benchmark tools such as ATTO Disk Benchmark and Iometer are helpful indicators, but should not be considered the ultimate determining factor. That factor should be measured in actual user experience of real-world applications. Benchmark Reviews includes both bandwidth benchmarks and application speed tests to present a conclusive measurement of product performance.
- Motherboard: MSI Z170A GAMING M7 Socket LGA 1151
- Processor: 4.0GHz Intel Core i7-6700K Skylake CPU
- System Memory: 16GB DDR4 2133MHz
- Operating System: Microsoft Windows 10
Storage Hardware Tested
The following storage hardware has been used in our benchmark performance testing, and may be included in portions of this article:
- Crucial RealSSD-C300 CTFDDAC256MAG-1G1 256GB SATA 6Gb/s MLC SSD
- Crucial m4 CT256M4SSD2 256GB SATA 6Gb/s MLC SSD
- Crucial M550 Solid State Drive515GBCT512M550SSD1
- Crucial MX100 Solid State Drive 512GBCT512MX100SSD1
- Crucial BX100 Solid State Drive 500GB CT500BX100SSD1
- Intel SSD 311 Series Larson Creek SSDSA2VP020G2E
- Intel SSD 320 Series MLC Solid State Drive SSDSA2CW160G3
- Intel SSD 335 Series Solid State Drive SSDSC2CT240A4K5
- Intel SSD 520 Series MLC Solid State Drive SSDSC2CW240A3
- OCZ Agility 2 OCZSSD2-2AGTE120G 120GB MLC SSD
- OCZ Agility 3 AGT3-25SAT3-240G 240GB MLC SSD
- OCZ Vertex 2 OCZSSD2-2VTXE120G 120GB MLC SSD
- OCZ Vertex 3 VTX3-25SAT3-240G 240GB MLC SSD
- OCZ Vertex 3.20 MLC SSD VTX3-25SAT3-240G.20 MLC SSD
- OCZ Vertex 4 VTX4-25SAT3-256G MLC SSD
- OCZ Vertex 450 VTX450-25SAT3-256G MLC SSD
- OCZ Vertex 460VTX460-25SAT3-240G MLC SSD
- OCZ Octane OCT1-25SAT3-512G MLC SSD
- OCZ Vector VTR1-25SAT3-256G MLC SSD
- OCZ Vector 150VTR150-25SAT3-240G MLC SSD
- Patriot Torqx 2 PT2128GS25SSDR 128GB MLC SSD
- WD SiliconEdge-Blue SSC-D0256SC-2100 256GB MLC SSD
- AS SSD Benchmark 1.6.4067.34354: Multi-purpose speed and operational performance test
- ATTO Disk Benchmark 2.46: Spot-tests static file size chunks for basic I/O bandwidth
- CrystalDiskMark 3.0.1a by Crystal Dew World: Sequential speed benchmark spot-tests various file size chunks
- Iometer 1.1.0 (built 08-Nov-2010) by Intel Corporation: Tests IOPS performance and I/O response time
- Finalwire AIDA64: Disk Benchmark component tests linear read and write bandwidth speeds
- Futuremark PCMark Vantage: HDD Benchmark Suite tests real-world drive performance
Test Results Disclaimer
This article utilizes benchmark software tools to produce operational IOPS performance and bandwidth speed results. Each test was conducted in a specific fashion, and repeated for all products. These test results are not comparable to any other benchmark application, neither on this website or another, regardless of similar IOPS or MB/s terminology in the scores. The test results in this project are only intended to be compared to the other test results conducted in identical fashion for this article.