Solid State Drives (SSDs) have become increasingly popular in computers over the last decade, providing significant performance improvements over traditional hard disk drives (HDDs). With no moving parts, SSDs allow for much faster read and write speeds. However, some users wonder if combining multiple SSDs together in a RAID 0 array can provide additional performance benefits.
What is RAID 0?
RAID stands for Redundant Array of Independent Disks. It is a data storage technology that combines multiple disk drives together to improve performance, capacity, or reliability. There are several different RAID levels, each with its own advantages and tradeoffs.
RAID 0 is also known as disk striping. It spreads data evenly across two or more disks with no parity or redundancy. This allows for parallel access to the data on each drive for increased speed. However, it also increases the risk of data loss if one drive fails, since there is no backup copy of the data. The storage capacity of a RAID 0 array is equal to the total capacities of all the drives added together.
Do SSDs Benefit from RAID 0?
Whether SSDs can benefit from RAID 0 is a complex question with arguments on both sides. Here are some of the key considerations:
Potential Benefits of SSD RAID 0
- Increased read/write performance – Spreading data across multiple SSDs allows for simultaneous access, increasing overall throughput.
- Better scaling – Adding more SSDs to the array can lead to (almost) linear performance improvements.
- Larger capacity – Combining multiple smaller SSDs can be cheaper than a single large SSD for a given capacity.
Potential Drawbacks of SSD RAID 0
- Diminishing returns – Modern SSDs already have very fast access times, limiting the gains of striping data.
- Increased risk of failure – Data loss is more likely with more disks in the array.
- Write amplification – RAID 0 can increase the number of write operations, wearing down SSDs faster.
- CPU/storage overhead – Processing and coordinating striped data has a computational cost.
SSD RAID 0 Benchmark Results
Numerous benchmarks have been conducted to quantify the real-world differences between standalone SSDs and SSD RAID 0 arrays. Here are some sample results:
| Configuration | Read Speed | Write Speed |
|---|---|---|
| 1x SATA SSD | 550 MB/s | 520 MB/s |
| 2x SATA SSDs in RAID 0 | 980 MB/s | 900 MB/s |
| 1x NVMe SSD | 3100 MB/s | 1500 MB/s |
| 2x NVMe SSDs in RAID 0 | 5200 MB/s | 3000 MB/s |
These benchmarks show that RAID 0 can provide a significant boost in both read and write speeds for both SATA and NVMe SSDs. The speedup is close to linear scaling for two drives. However, the performance gains are more substantial for SATA SSDs, which have lower individual throughput. For already fast NVMe SSDs, the RAID 0 improvements are smaller in percentage terms.
When Does SSD RAID 0 Make Sense?
Given the complex performance tradeoffs, SSD RAID 0 arrays only make sense in certain usage scenarios:
- On bandwidth-constrained SATA ports, combining multiple SATA SSDs can overcome interface bottlenecks.
- For workloads with sustained reads and writes rather than sporadic I/O.
- When consistently maximum disk performance is critical for applications like video editing, scientific computing, financial analysis, etc.
- In enterprise environments where high resiliency is already provided at the system level.
For typical consumer usage, gaming, and boot drives, the risks and costs of RAID 0 with SSDs usually outweigh the small performance gains. A single modern NVMe SSD often provides adequate speeds without the hassle and data redundancy concerns of RAID 0.
Considerations for Implementing SSD RAID 0
If pursuing an SSD RAID 0 array makes sense for your use case, here are some tips for implementation:
- Use identical SSD models – Differences in performance between drives will reduce efficiency.
- Ensure SSDs have similar wear levels – Avoid combining new and old SSDs.
- Use SATA ports connected to the same storage controller for stability.
- Use NVMe ports connected via PCIe switch or MUX for best NVMe RAID performance.
- Install RAID drivers during OS installation for best management and stability.
- Back up your RAID 0 array regularly due to the higher risk of data loss.
Alternatives to SSD RAID 0
If the tradeoffs of implementing RAID 0 with SSDs are unacceptable for your use case, there are a few alternatives to consider:
Single Larger Capacity SSD
Rather than combining multiple smaller SSDs, purchasing a single high capacity SSD may be more cost effective and does not incur RAID management overhead.
SSD Caching
Using an SSD as a cache for a larger traditional hard drive or disk array can provide some performance benefits without requiring RAID management.
NVMe RAID Using BIOS/OS Support
Some modern motherboards support OS-transparent NVMe RAID through the BIOS and chipset drivers. This avoids the need for traditional software RAID and associated overhead.
External SSD RAID Enclosure
Placing multiple SSDs in a dedicated external RAID enclosure can centralize and simplify RAID 0 management.
Conclusion
The potential for SSD RAID 0 to improve bandwidth and storage performance is real, but constrained by drive interface bottlenecks and diminishing marginal returns. The loss of redundancy also increases data integrity risks. For many consumer use cases, a single modern NVMe SSD provides good enough performance without RAID complexity. RAID 0 makes the most sense when bandwidth is a constraint and maximum disk throughput is imperative. Careful hardware selection and configuration is needed to properly balance performance, cost, and data resilience when implementing SSD RAID 0.
