NAS (network-attached storage) refers to file-level data storage servers that are connected to a computer network, allowing access to multiple users and devices (1). SSD (solid state drive) refers to a storage device that uses flash memory chips rather than spinning hard disk platters to store data (2).
Using SSDs in NAS can provide benefits like faster read/write speeds, lower latency, reduced power consumption, less noise, and improved reliability due to no moving parts. However, SSDs have lower storage capacity per dollar compared to HDDs. SSDs also have limitations on the number of write cycles before failure, although modern SSDs are rated for very high endurance. Overall, SSDs offer excellent performance for NAS applications if the higher cost per gigabyte is acceptable.
(1) https://www.techtarget.com/searchstorage/definition/network-attached-storage
(2) Definition of SSD from general knowledge
Cost Comparison
When it comes to cost per gigabyte, traditional hard disk drives (HDDs) are generally less expensive than solid state drives (SSDs). HDDs can offer more storage capacity at a lower price point. According to AWS, data storage on an SSD typically costs around $0.08-$0.10 per GB, while HDD storage is significantly cheaper at around $0.02-$0.04 per GB. As noted on Reddit, since 2011 the cost per TB for HDDs has steadily declined from $30 to $13 per TB.
However, SSD prices have been dropping over time as well. And for many applications, the performance benefits of SSDs make them worth the higher price per gigabyte. HDDs are better suited for long term data archives where access speed is not a priority. But for applications like boot drives, application storage, gaming, and more, SSDs provide a major speed advantage that often justifies the higher cost per gigabyte.
Performance
One of the key benefits of using SSDs in a NAS is faster read and write speeds compared to traditional hard disk drives (HDDs). SSDs have no moving parts and use flash memory, allowing data to be accessed almost instantly. According to tests by Reddit users on the r/homelab subreddit, SSDs in a NAS can achieve sequential read speeds over 500 MB/s and writes around 300 MB/s [1]. In comparison, a NAS with HDDs may only reach speeds of 100-200 MB/s. This performance advantage makes SSDs better suited for applications that require fast data access, like hosting virtual machines, databases, or media streaming.
The faster speed of SSDs translates to shorter loading times when accessing files over the network. Opening files, loading programs, transferring data – everything happens noticeably quicker with SSD-based storage. For home or office users who access the NAS frequently, this can lead to significant time savings and improved productivity.
In summary, the high read and write speeds of SSDs result in much better real-world performance compared to HDDs when used in a NAS. The speed boost can be especially valuable for demanding applications.
Reliability
SSDs tend to be more reliable than HDDs for most typical use cases, though HDDs can have some advantages in niche applications. According to research by cloud storage firm Backblaze, SSDs had an annual failure rate of just 1.2%, compared to 1.8% for HDDs [1]. However, SSDs can wear out over time with excessive writes. The cells in an SSD have a limited number of erase cycles before they become unusable. Consumer SSDs are typically rated for anywhere from 100 to over 5,000 write cycles. In a busy NAS where data is rewritten frequently, an SSD may wear out faster than a HDD over time.
Power Consumption
SSDs use significantly less power than traditional HDDs. According to testing by Windowscentral, SSDs have a power draw range of 5-20 watts, while HDDs use between 5.7-9.4 watts. The lower power draw of SSDs is because they have no moving mechanical parts like the spinning platters and drive motors found in HDDs.
This makes SSDs better suited for laptops and mobile devices where battery life is important. For a NAS or server that will run 24/7, the lower power needs of an SSD can also lead to significant energy savings over time. Users on Reddit highlight the power efficiency benefits of SSDs, though note the much higher $/TB cost compared to HDDs.
Noise Level
One of the most noticeable differences between SSDs and HDDs is noise level. SSDs contain no moving mechanical parts, so they operate completely silently. HDDs rely on spinning platters and moving read/write heads, which generate audible noise during operation. As one forum user noted, “SSDs make no noise. Period. Nothing to ‘move’.” (https://forums.tomshardware.com/threads/noise-like-a-mechanical-hdd-during-ssd-activity.3755545/). In contrast, the physical components inside HDDs inevitably produce noise from friction and vibration.
For home or office use, the silent operation of SSDs is preferable if noise is a concern. The noise levels from HDDs can range from a quiet hum to loud clicks and spins depending on the model and workload. For quiet computing environments or noise-sensitive activities like recording audio, SSDs are the clear winner. Even for gaming and general use, the silence of SSDs is appreciated by many users. As Quora users confirm, “Yes, SSD drives generally run quieter than HDD drives. This is because SSDs have no moving parts, unlike HDDs which have spinning disks and heads” (https://www.quora.com/Do-SSD-drives-run-quieter-than-HDD-drive). When evaluating storage options, keep the major noise differences between SSDs and HDDs in mind.
Heat Output
SSDs generally run much cooler than traditional HDDs. This is because SSDs have no moving parts, unlike the spinning platters and moving heads of a traditional hard drive. According to Tom’s Hardware, SSDs are able to operate at higher temperatures than HDDs. And as noted on Quora, the lack of moving parts allows SSDs to run cooler. Reddit users also agree that SSDs produce about half the heat of HDDs.
Capacity
When it comes to storage capacity, HDDs currently offer more storage per drive compared to SSDs. HDDs are commonly available in 500 GB to 1 TB sizes, while SSDs generally range from 64 GB to 4 TB per drive (Source). For example, some of the largest HDDs today can store up to 22 TB per drive, while the largest SSDs top out around 100 TB per drive (Source). The higher storage density of HDDs means they provide more gigabytes per dollar spent compared to SSDs. If you need massive amounts of storage space on a budget, HDDs are likely the better choice.
Recommendations
SSDs tend to be better suited for NAS configurations that need higher performance in terms of speed and lower latency, while HDDs are usually better for higher capacity bulk storage at a lower cost per gigabyte.
Here are some ideal use cases for SSDs in a NAS:
- Storing files that need faster access like databases, virtual machines, application files or scratch space.
- Handling lots of small file transactions or random reads/writes.
- Applications that require consistently low latency like video editing or gaming.
- Lower capacity NAS (under 50TB) where cost is less of a concern.
HDDs are still the better choice when:
- Raw storage capacity is the priority over performance.
- Archiving infrequently accessed data like media libraries or backups.
- Workloads involve mostly sequential reads/writes.
- Building out a high capacity NAS on a budget.
In summary, if your workload benefits more from speed than density, SSDs can be ideal for NAS. But for most bulk storage needs, HDDs are more cost effective.
Conclusion
When evaluating whether SSDs are a good choice for NAS, there are pros and cons to consider. On the pro side, SSDs offer faster performance, lower power consumption, cooler operating temperatures, and less noise than traditional HDDs. However, SSDs come at a higher price point and generally have lower capacities.
Overall, SSDs can work well for NAS in certain scenarios, but may not be the best choice universally. SSDs are a great option if you need the improved performance and lower power draw. The extra speed is useful for media streaming, database access, virtual machines, and other demanding workloads. However, for bulk data storage and backups, the higher price and lower capacity of SSDs makes HDDs a better value.
In the end, choosing between an SSD or HDD NAS comes down to your specific needs and priorities. For a blend of speed and high capacity, a hybrid NAS with both SSD caching and HDD storage can offer a good middle ground. But for most home and small business users focused on high capacity networked storage and backups, HDD-based NAS still reigns supreme when factoring price, capacity, and lifespan.