What is NVMe RAID?
NVMe RAID (Non-Volatile Memory Express RAID) combines multiple NVMe SSDs into a single logical unit to improve performance and/or reliability. Like traditional RAID with HDDs, NVMe RAID allows for configurations like RAID 0, 1, 5, etc. However, because NVMe SSDs are much faster than traditional HDDs, NVMe RAID provides higher bandwidth and lower latency compared to standard RAID (source).
The key advantages of NVMe RAID include:
- Increased read/write speeds due to spreading I/O across multiple SSDs
- Higher bandwidth since multiple NVMe drives can utilize more PCIe lanes
- Lower latency thanks to parallel access and NVMe SSD responsiveness
- Added fault tolerance with redundant RAID modes like RAID 1 or 5
Compared to a single NVMe SSD, NVMe RAID can offer 2-4x higher sequential read/write performance depending on the RAID mode and number of drives. The trade-off is increased cost and complexity compared to a single NVMe drive solution.
When to Use NVMe RAID
NVMe RAID can provide significant performance benefits for applications that demand very high I/O throughput and low latency. Some common use cases where NVMe RAID makes sense include:
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High-performance computing clusters running data-intensive simulations, machine learning, or other complex workloads. The aggregated bandwidth of multiple NVMe SSDs in RAID 0 can reduce job completion times (Source: https://www.quora.com/Should-I-use-NVMe-RAID-mode).
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Real-time video editing requiring high bandwidth to read/write large video files. NVMe RAID provides the throughput to smoothly edit 8K or multi-stream footage.
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Virtualized environments with many VMs contending for storage I/O. RAID 0 can deliver the IOPS needed for optimal VM density.
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Critical applications needing maximum uptime. RAID 1 mirroring provides fault tolerance if an SSD fails.
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Database servers supporting high volumes of transactions. The parallelism of NVMe RAID increases responsiveness.
In summary, for mission-critical workloads that can benefit from blazing fast speeds and maxed-out I/O, NVMe RAID is purpose-built for the job.
NVMe RAID Performance
RAID 0 configurations with multiple NVMe drives can provide significant performance improvements over a single NVMe drive. According to tests by Reddit user u/cruisin5268d, benchmark scores increased dramatically when going from 1 to 2 NVMe drives in RAID 0 (Source). Specifically, sequential read speeds improved from 3.3GB/s to 6.5GB/s, while sequential writes increased from 3GB/s to 5.8GB/s.
However, the performance gains diminish as you add more NVMe drives in RAID 0. Adding a 3rd and 4th NVMe drive only provided an additional 15-20% increase in read/write speeds over 2 drives. At a certain point, the RAID controller and PCIe bus become the bottleneck, limiting how much extra performance you can extract from additional NVMe drives (Source).
So while NVMe RAID 0 can provide a noticeable boost over a single drive, the benefits taper off after 2-3 drives. You won’t see anywhere close to a linear performance increase as you add more NVMe SSDs. Carefully consider whether the added cost is worth the diminishing returns.
NVMe RAID Reliability
NVMe RAID can improve reliability through redundancy. By combining multiple NVMe drives in a RAID 1, 5, 6, 10 configuration, data is mirrored or striped across multiple drives. This way, if one drive fails, data can be rebuilt from the remaining drives. According to one source, “NVMe Drives are just as reliable as other SSDs. That said, I still run RAID, plus have backups. Yes, software RAID is very reliable these days” (Source). RAID increases fault tolerance and uptime. However, RAID is not a backup. Regular backups are still recommended.
The redundancy of RAID can protect against drive failure and improve reliability. But you still need a good quality NVMe drive. Look for enterprise-grade drives with high endurance ratings if reliability is critical. Consumer NVMe drives may be less reliable for heavy workloads (Source).
NVMe RAID Compatibility
NVMe RAID compatibility depends on having motherboard and CPU chipset support. Most modern AMD and Intel chipsets include built-in NVMe RAID capabilities. For AMD, the X470, X570, B550, and TRX40 chipsets all support NVMe RAID natively. On the Intel side, the Z390, Z490, Z590, and X299 chipsets have integrated NVMe RAID support[1]. Older chipsets may require purchasing a separate NVMe RAID controller card to enable NVMe array functionality.
At the operating system level, Windows 10 and most modern Linux distributions include NVMe RAID drivers and can detect and manage NVMe RAID arrays. However, some older operating systems like Windows 7 lack native NVMe RAID support and would require updated drivers to work with NVMe RAID setups[2]. Overall, NVMe RAID compatibility should not be an issue with a reasonably modern hardware platform and OS.
NVMe RAID Setup
Setting up NVMe RAID involves configuring the RAID mode in your computer’s BIOS or UEFI settings. The steps may vary depending on your motherboard, but generally involve:
1. Accessing the BIOS/UEFI settings on bootup. This is usually done by pressing a function key like F2, F10 or Delete during the initial boot sequence.Source
2. Enabling RAID mode for the NVMe ports/slots. This setting may be under “Peripherals”, “Storage Configuration” or a similar section in the BIOS.Source
3. Creating the RAID array with the NVMe drives. Select the drives to include and choose the RAID mode, often RAID 0 for performance or RAID 1 for redundancy.
4. Saving changes and exiting the BIOS/UEFI to complete setup.
Some motherboards have software utilities that can configure NVMe RAID as well. Consult your motherboard manual for details on accessing BIOS settings and NVMe RAID configuration.
NVMe RAID Management
Properly managing NVMe RAID arrays is crucial for ensuring optimal performance and reliability. There are several key tools and best practices to keep in mind:
Most NVMe RAID controllers provide management software utilities for monitoring disk health, reviewing event logs, changing RAID modes, rebuilding failed drives, and more. For example, the LSI MegaRAID Storage Manager is a popular solution for managing MegaRAID controllers. These tools allow close monitoring and easy reconfiguration of NVMe RAID volumes [1].
It’s recommended to proactively monitor disk SMART attributes through the management utility and replace failing drives before multiple failures occur. Most controllers can continue operating safely even during rebuilds. However, it’s best to avoid heavy write loads until rebuilds complete [2].
Maintaining current firmware on the NVMe RAID controller is also important for compatibility with new drives and fixing bugs. Some tools allow scheduling patrol reads to detect latent disk errors. Overall, leveraging the management software provides the control needed to keep NVMe RAID healthy.
NVMe RAID Limitations
While NVMe RAID can provide some benefits, it also comes with some significant drawbacks that users should carefully consider before implementing it.
One major downside is cost. Building an NVMe RAID array requires purchasing multiple high-capacity NVMe SSDs, which are substantially more expensive than standard SATA SSDs. The financial investment can be prohibitive for many users (Source).
NVMe RAID also introduces complexity. Properly configuring and managing an NVMe RAID array requires advanced technical knowledge. For novice users, this complexity can be overwhelming and lead to improperly setup arrays or degraded performance (Source).
In some cases, NVMe RAID can actually result in performance overhead versus a single NVMe SSD. The RAID controller and reconstruction of arrays introduces latency that diminishes returns on raw throughput. For many real-world workloads, NVMe RAID provides negligible gains over a single performant NVMe SSD (Source).
Overall, while NVMe RAID has its benefits, the downsides of cost, complexity, and limited performance gains make it impractical for most average users. Carefully evaluating one’s specific use case is recommended before investing in an NVMe RAID setup.
Alternatives to NVMe RAID
While NVMe RAID offers performance and redundancy benefits, it also comes with downsides like increased cost and complexity. There are alternatives that may better suit your needs.
For improved performance without RAID, consider upgrading to a single faster NVMe SSD drive. Newer generation NVMe drives offer incredible sequential read/write speeds exceeding 6,000 MB/s. A faster single drive avoids the RAID overhead while still providing a performance boost.
Caching and tiering solutions like PrimoCache can leverage a small SSD as cache for a larger traditional hard drive. This delivers SSD speeds for frequently accessed data while storing bulk capacity on cheaper HDDs. Caching maximizes performance per dollar compared to an all-SSD RAID array.
Storage clustering and scale-out solutions like StorPool distribute IOPS across drives. By balancing workloads, performance scales linearly with each added node. Clustering also provides redundancy without traditional RAID and its overhead.
Before implementing NVMe RAID, evaluate if advanced caching, tiering, clustering or simply upgrading to faster NVMe drives better suit your needs and budget.
Conclusion
In summary, NVMe RAID can provide faster speeds and better performance compared to a single NVMe drive, but it comes with drawbacks like decreased reliability and compatibility issues. NVMe RAID is best suited for use cases that need high bandwidth and low latency like video editing, scientific computing, financial analysis and other data-intensive workloads.
The potential performance benefits of NVMe RAID need to be weighed against the costs of implementation and potential downsides. Factors like your workloads, budget, motherboard and operating system compatibility should be considered.
For most consumer use cases, a single high capacity NVMe drive will provide good enough performance without the hassle of configuring RAID. NVMe RAID requires thoughtful setup and administration for maximum benefit. Overall, NVMe RAID can be beneficial for the right use case, but isn’t necessary for the average user.
