Is network-attached storage fast?

Network-attached storage (NAS) provides centralized file storage and backup for multiple users and devices on a network. With the rise of high-resolution media files and the need to access data quickly from anywhere, the speed and performance of a NAS system is critical for many home and business users. Slow file transfers, lagging access, and bottlenecks can significantly impact productivity and user experience. This article examines the various factors that influence NAS performance, including drive types, network connectivity, RAID configurations, caching, encryption overhead, and concurrent multi-user access. We’ll break down how these elements contribute to real-world speeds to help determine if modern NAS solutions can provide the fast and responsive storage users expect.

NAS Overview

Network-attached storage (NAS) is dedicated file storage that enables multiple users and heterogeneous client devices to retrieve data from centralized disk capacity. NAS systems are flexible and scale out, meaning that as you need additional storage, you can add to NAS capacity by adding more drives or devices (TechTarget, 2022).

A NAS device is connected directly to a local area network, most commonly via Ethernet. This allows multiple users and heterogeneous client devices to retrieve data from centralized disk capacity. A NAS unit has its own IP address, can connect to other IP networks, and can often be accessed remotely over the internet (Seagate, 2022).

The key benefit of NAS systems is that they allow organizations to spread and optimize storage capacity across the network. Files can be accessed from different locations and systems, rather than being tied to a single device. NAS provides more flexibility than alternatives like direct attached storage (DAS) or storage area networks (SAN). NAS capacity can easily be expanded as needed without disruption (TechTarget, 2022).

NAS Interfaces

NAS systems typically connect to a local area network (LAN) using standard Ethernet technology. Most consumer and small business NAS devices have 1Gbps Ethernet ports, which provide transfer speeds up to 125MB/sec.[1] Higher-end NAS systems aimed at enterprise use may include 10Gbps Ethernet interfaces capable of speeds up to 1.25GB/sec.[2]

Some NAS devices also include Thunderbolt 3 ports, which have a maximum bandwidth of 40Gbps and can achieve transfer speeds up to 2.8GB/sec. However, both ends of the connection must have Thunderbolt 3 ports to reach these speeds. When connecting to a 1Gbps Ethernet network, Thunderbolt 3 offers no speed advantage.[3]

In summary, standard 1Gbps Ethernet connections limit most consumer NAS devices to speeds of around 100MB/sec. Upgrading to 10Gbps Ethernet or using Thunderbolt 3 can boost speeds up to 1-2GB/sec. But network and drive factors also impact overall NAS performance.




Drive Types

When it comes to NAS drives, there are two main options: hard disk drives (HDDs) and solid state drives (SSDs). HDDs have traditionally been used in NAS devices due to their high capacity and low cost per terabyte. However, SSDs are gaining popularity in NAS setups due to their performance advantages.

SSDs have no moving parts and can provide much faster read/write speeds compared to traditional HDDs. Average sequential read/write speeds for SATA SSDs can exceed 500 MB/s, while HDDs max out around 200 MB/s (1). This makes SSDs better suited for applications that demand faster data access like video editing or gaming. SSDs also provide lower latency and faster access times.

However, HDDs still have the benefit of much higher storage capacity per dollar spent. For example, 8TB SATA SSDs cost significantly more than 8TB HDDs (2). For bulk data storage and backups, HDDs can provide more storage capacity for the budget. HDDs also have longer lifespan with writes before failure.

For the best NAS performance, using SSDs for active data and applications while storing bulky backups and media files on larger HDDs can provide a good balance of speed and capacity. However, even an all-SSD NAS will provide substantial performance gains over traditional HDD configurations.


RAID Configurations

RAID can have a significant impact on NAS performance depending on the configuration. RAID 0 stripes data across multiple drives with no parity or mirroring, which improves read/write speeds, but provides no redundancy. According to Synology, RAID 0 can double disk performance compared to a single drive.

RAID 1 mirrors data across two drives to provide redundancy. Reads can be faster since data can be accessed from both drives, but writes are slower since data has to be written twice. RAID 10 combines mirroring and striping for improved performance and redundancy. Backblaze found RAID 10 offered a good balance of performance and protection.

Higher RAID levels like 5 and 6 provide more parity and redundancy but lower performance as more calculations are required for writes. The optimal RAID level depends on the desired balance of speed, redundancy, and number of drives.


One way to improve the performance of a NAS is by using caching, which stores frequently accessed data in faster memory. This allows the NAS to retrieve this data quicker instead of needing to access slower mechanical hard drives. Two common caching methods for NAS are RAM caching and SSD caching.

RAM caching utilizes the NAS device’s onboard RAM to cache frequently accessed data. This provides fast read and write speeds since RAM is much faster than hard drives. When a file is requested, the NAS will first check the RAM cache to see if it’s available there before accessing the hard drives. This avoids the slower mechanical drive access for common operations (BuffaloTech). The more RAM available, the larger the cache size can be.

However, one downside of RAM caching is that it’s volatile and doesn’t persist if the NAS is powered off. The cache will need to be rebuilt on reboot. So it’s best suited for frequently reused files rather than long-term storage. Overall, RAM caching is an easy way to boost NAS performance for common workloads without additional hardware.

Multi-User Access

When multiple users access and transfer data to or from a NAS simultaneously, it can put strain on the system and impact performance. According to Backblaze, concurrent connections from multiple users reading, writing, or accessing the NAS at once is one factor that can negatively affect speed.

On the Synology subreddit, one user pointed out how enabling SMB Multichannel allowed them to double their transfer speeds compared to standard link aggregation when multiple users were accessing the NAS. This highlights how the network protocol used, and specific NAS features like multichannel, impact performance when there are concurrent connections.

According to the Synology forums, running simultaneous NAS speed tests from multiple PCs is a good way to benchmark the actual throughput when multiple users access a NAS concurrently. Checking network settings like MTUs and enabling features like SMB multichannel, as well as monitoring NAS resource usage during multi-user transfers, can help optimize performance.

Encryption Overhead

Encryption protects data on a NAS device by scrambling the data so that it can only be accessed by authorized users with the decryption key. However, encrypting and decrypting data does come with a performance cost (Serverfault, 2011). The encryption algorithms require additional computing resources from the NAS which can result in slower transfer speeds and longer operation times.

According to TechTarget (2022), enabling encryption on a NAS can reduce performance by 20-30%. The performance impact depends on the encryption method used, with full disk encryption generally having a higher overhead than individual file and folder encryption. The loss in performance is most noticeable when writing new data to the NAS.

There are ways to optimize encrypted NAS devices to minimize the performance impact as much as possible. Using a hardware encryption chip rather than software encryption reduces the demand on the NAS processor. Caching frequently accessed data can improve read speeds. And selecting faster drives like SSDs helps offset the encryption burden with their naturally higher performance (LinkedIn, 2023).

Network Factors

How your NAS is connected to other devices on your network can significantly impact transfer speeds. The network topology and switches used play a key role.

For optimal performance, it’s recommended to connect your NAS directly to a gigabit (or better) network switch using Cat 5e or Cat 6 Ethernet cabling. The switch should also have enough bandwidth to handle multiple simultaneous file transfers without bottlenecking. Many consumer routers have 100 Mbps ports or Fast Ethernet switches built-in, which can hamper NAS speeds compared to a dedicated Gigabit switch according to discussions on Tom’s Hardware forums.

Higher-end SMB/enterprise switches like 10 gigabit models provide even faster potential throughput for demanding workloads, but come at a higher cost. Connecting multiple Ethernet cables from the NAS to the switch utilizing link aggregation can also boost performance by increasing bandwidth according to Reddit users. Avoid lower quality or unmanaged switches that can lead to congestion.

In summary, using a dedicated Gigabit or better switch and quality cabling is recommended for peak NAS performance across your network. This ensures the full speed potential of the drives and interfaces is realized.


In summary, there are several key factors that impact the performance of network-attached storage (NAS):

  • NAS interface – Faster interfaces like 10GbE and Thunderbolt provide higher throughput.

  • Drive types – Solid-state drives (SSDs) offer faster read/write speeds than traditional hard disk drives (HDDs).

  • RAID configuration – RAID 0 provides better performance but less redundancy. RAID 10 balances speed and protection.

  • Caching – Additional RAM or SSD caching accelerates common workloads.

  • Multi-user access – More concurrent connections put higher demand on the NAS.

  • Encryption – Encryption introduces computational overhead that can reduce throughput.

  • Network factors – A faster local network (e.g. 10GbE) allows the NAS to operate at full speed.

By selecting the right combination of these options, both home and business users can build a high performance NAS tailored to their needs and budget.