2-Bay vs 6-Bay NAS Devices: Which Should You Buy?
As an Amazon Associate we earn from qualifying purchases. Links on this page are affiliate links.
Choosing between 2-Bay vs 6-Bay network attached storage depends on your capacity needs. Both devices provide centralized file management and backup capabilities for home or small office use. The Buffalo LinkStation 220 offers a compact, pre-configured solution with included drives. The Synology DS620slim provides a diskless chassis with higher expandability and performance features. You must decide based on whether you prefer immediate readiness or future scalability.
Key differences
| Aspect | Buffalo LinkStation 220 4TB 2-Bay NAS | Synology 6-Bay 2.5 Inch NAS DS620slim |
|---|---|---|
| Number of Bays | 2-Bay | 6-Bay |
| Included Storage | 4TB (2x2TB) | Diskless |
| RAM | not listed | 2GB DDR3L (expandable to 6GB) |
| Drive Form Factor | not listed | 2.5 Inch |
| RAID Support | RAID 0, RAID 1 | Flexible RAID configuration |
Which one should you choose?
Choose Buffalo LinkStation 220 4TB 2-Bay NAS if
- You want a ready-to-use system with drives included and do not need to buy additional components.
- You have limited space and prefer a smaller footprint for your home office or living area.
- You only need basic RAID 1 redundancy for protecting personal photos and documents.
Choose Synology 6-Bay 2.5 Inch NAS DS620slim if
- You need to store large amounts of data and want the flexibility to add up to six drives later.
- You require higher performance for tasks like 4K video transcoding or faster file transfers.
- You plan to expand your storage capacity significantly over time without replacing the entire unit.
Verdict: The Buffalo LinkStation 220 is the better choice for users who want a simple, plug-and-play experience with no immediate need for expansion. The Synology DS620slim suits those who anticipate growing storage needs and want the performance headroom for more demanding tasks. Your decision should rest on whether you value immediate convenience or long-term scalability.
2-Bay vs 6-Bay NAS Comparison
Number of Bays
The Buffalo LinkStation 220 features two drive bays, designed for users who need a compact storage solution. It ships with 4TB of capacity, using two 2TB drives in RAID 1 for automatic backup, though you can switch to RAID 0 for full 4TB use. The Synology DS620slim offers six drive bays, providing significantly more flexibility. It is diskless, meaning you install your own drives. This allows you to scale capacity much higher than the pre-configured Buffalo unit, accommodating both 2.5-inch HDDs and SSDs for varied performance needs.
RAM Capacity
Memory plays a key role in handling multiple tasks and concurrent connections. The Synology DS620slim comes with 2GB of DDR3L memory, which is expandable up to 6GB. This upgrade path supports more complex operations and better multitasking. The Buffalo LinkStation 220 data does not specify its RAM capacity. Without this information, you cannot compare the raw processing headroom for heavy workloads. The Synology unit provides a clear advantage in memory specifications, offering both initial capacity and future expandability for demanding environments.
Included Storage
The Buffalo LinkStation 220 includes 4TB of storage out of the box, with two 2TB drives pre-installed. This ready-to-use approach simplifies setup for home users who want immediate capacity without purchasing separate drives. The Synology DS620slim is diskless, meaning it contains no internal storage. You must buy drives separately to use it. While this adds initial cost and effort, it offers the freedom to choose drive types and capacities that fit your specific budget and long-term growth plans, rather than being locked into a fixed 4TB package.
Form Factor
Physical size affects where you can place your NAS and how it fits in your space. The Buffalo LinkStation 220 measures 10 inches in width, 8.82 inches in height, and 5.04 inches in length, weighing 1 pound. It is a standard desktop footprint. The Synology DS620slim is described as mini-sized, measuring 6.89 inches in length, 5.94 inches in width, and 4.76 inches in height, weighing 3.09 pounds. Despite having three more bays, the Synology unit is more compact in overall dimensions, making it easier to fit into smaller spaces while offering greater density.
RAID Support
RAID configurations determine data redundancy and performance. The Buffalo LinkStation 220 supports RAID 0 and RAID 1. RAID 1 provides automatic backup by mirroring data across both drives, ensuring safety if one drive fails. RAID 0 offers full capacity but no redundancy. The Synology DS620slim provides better RAID flexibility, allowing you to configure various RAID levels across its six bays. This includes options for higher redundancy, performance, or a mix of both. The Synology unit offers superior flexibility for protecting larger amounts of data across more drives.
Which NAS fits your storage needs
Home users wanting plug-and-play simplicity
The Buffalo LinkStation 220 ships with 4TB of storage already installed. You get a closed system with SSL encryption for secure file transfers. It supports RAID 1 for automatic backup or RAID 0 for full capacity. This option is ideal if you want a compact, pre-configured solution without managing drive purchases separately.
Users needing high capacity and expansion
The Synology DS620slim offers six drive bays for 2.5-inch drives. It supports advanced file systems with up to 65,000 system-wide snapshots. You can expand the 2GB DDR3L memory up to 6GB. This device is best for those requiring significant storage volume and flexibility to configure multiple drives for large data sets.
Small offices requiring video transcoding
This Synology model features dual-channel H.265/H.264 4K video transcoding on the fly. It delivers over 220 MB/s reading speeds even under encrypted transmission. The six-bay design allows you to maximize work productivity with better RAID flexibility. It is suitable for environments that need fast access to media files.
Those prioritizing data security and privacy
The Buffalo LinkStation 220 features a closed system to reduce vulnerabilities from third-party apps. You can configure individual access restrictions for folders to ensure data remains private. It includes NAS Navigator utility for automated backups. This setup is perfect for users who want centralized storage with built-in security measures and no subscription fees.
Quick picks
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | Buffalo LinkStation 220 4TB 2-Bay NAS | home users needing simple 2-bay storage | Check price of Buffalo LinkStation 220 4TB 2-Bay NAS on Amazon |
| 2 | Synology 6-Bay 2.5 Inch NAS DS620slim | Compact high-density 2.5-inch drive storage | Check price of Synology 6-Bay 2.5 Inch NAS DS620slim on Amazon |
The products compared
Buffalo LinkStation 220 4TB 2-Bay NAS
Best for: home users needing simple 2-bay storage
- Number of Bays
- 2-Bay (what this guide is about)
- Drive Bays
- 2-Bay
- Included Storage
- 4TB
- RAID Support
- RAID 0, RAID 1
- Intended Use
- Home Users
- Dimensions
- 5.04 × 10 × 8.82 inches
View on Amazon: Buffalo LinkStation 220 4TB 2-Bay NAS Affiliate link
The BUFFALO LinkStation 220 is a 2-bay NAS designed for home users who need centralized storage. It ships with 4TB of included hard drives, offering 2TB of usable space in RAID 1 or 4TB in RAID 0. The device connects to your router for shared network access across Windows and macOS 15 and earlier. It features a closed system with SSL encryption to reduce vulnerabilities and includes backup utilities for automated data protection.
Pros
- Includes 4TB of storage in two 2TB drives
- Supports RAID 0 and RAID 1 configurations
- Closed system reduces third-party app vulnerabilities
- Includes NAS Navigator 2 for automated backups
- Compatible with Windows and macOS 15 and earlier
Cons
- Only supports macOS 15 and earlier versions
- No mention of compatibility with newer macOS 26
- Limited to 4TB total capacity in this configuration
Good fit if
- You need a simple, pre-configured 2-bay NAS
- You want included drives for immediate use
- You use Windows or older macOS systems
Skip if
- You require macOS 26 compatibility
- You need more than 4TB of storage
- You want advanced cloud features or app support
Verdict: BUFFALO LinkStation 220 4TB 2-Bay NAS is a straightforward choice for home users seeking basic, secure storage with included drives and RAID options, particularly those on Windows or older macOS systems.
Synology 6-Bay 2.5 Inch NAS DS620slim
Best for: Compact high-density 2.5-inch drive storage
- Number of Bays
- 6-Bay (what this guide is about)
- Drive Bays
- 6 Bay
- RAM Capacity
- 2GB DDR3L
- Included Storage
- Diskless
- Form Factor
- 2.5 Inch
- Dimensions
- 6.89 × 5.94 × 4.76 inches
View on Amazon: Synology 6-Bay 2.5 Inch NAS DS620slim Affiliate link
The Synology DS620slim is a 6-bay NAS designed for 2.5-inch drives. It includes 2GB of DDR3L memory, expandable to 6GB. The system supports dual-channel H.265/H.264 4K video transcoding. You get over 220 MB/s read speeds and 190 MB/s write speeds. The Btrfs file system allows for extensive snapshot capabilities. This unit suits users needing high density in a small footprint.
Pros
- Six bays for 2.5-inch HDDs and SSDs
- Dual-channel 4K video transcoding support
- Expandable memory up to 6GB
- High read and write throughput speeds
Cons
- Sold diskless with no drives included
- Only 2GB base memory is modest
- Limited to 2.5-inch drive form factor
Good fit if
- You need high storage density in a small space
- You want to use 2.5-inch drives for efficiency
- You require 4K video transcoding capabilities
Skip if
- You prefer pre-loaded drives for immediate use
- You need 3.5-inch drive capacity per bay
- You require more than 6GB of RAM
Verdict: Synology DS620slim 6-Bay NAS fits users who prioritize compact storage density and 2.5-inch drive efficiency over raw per-drive capacity.
Specifications side by side
| Spec | Buffalo LinkStation 220 4TB 2-Bay NAS | Synology 6-Bay 2.5 Inch NAS DS620slim |
|---|---|---|
| Drive Bays | 2-Bay | 6 Bay |
| RAM Capacity | not stated | 2GB DDR3L |
| Included Storage | 4TB | Diskless |
| RAID Support | RAID 0, RAID 1 | not stated |
| Form Factor | not stated | 2.5 Inch |
| Number of Bays | 2-Bay | 6-Bay |
| Intended Use | Home Users | not stated |
| Dimensions | 5.04 × 10 × 8.82 inches | 6.89 × 5.94 × 4.76 inches |
| Weight | 1 pounds | 3.09 pounds |
| Size | 4TB (2x2TB) | 6-bay; 2GB DDR3L |
| Color | Black | white |
| Model | LS220D0402 | DS620slim |
Frequently asked questions
Is a 2-bay NAS enough for a home user?
Yes, a 2-bay NAS is sufficient for basic home storage needs. The Buffalo LinkStation 220 is designed specifically for home users seeking simple, secure storage. It comes with 4TB of capacity pre-installed, which is adequate for personal photo libraries and document backups without requiring complex management.
What is the main difference between 2-bay and 6-bay NAS devices?
The primary difference lies in drive capacity and physical footprint. A 2-bay device like the Buffalo LinkStation 220 holds two drives, offering 4TB total. In contrast, a 6-bay unit such as the Synology DS620slim accommodates six drives, significantly increasing storage density. This allows for much larger data archives in a single chassis.
Can I expand storage on a 2-bay NAS?
You can expand storage by replacing the internal drives with larger ones, but you cannot add more drives to the chassis. The Buffalo LinkStation 220 is a fixed 2-bay system. To increase capacity, you would need to swap the existing 2TB drives for higher-capacity units, maintaining the two-drive limit.
Which NAS is better for small office backups?
A 6-bay NAS is generally better for small office backups due to higher capacity and redundancy options. The Synology DS620slim supports six drives, allowing for more robust RAID configurations. This provides greater data protection and storage volume compared to the 4TB limit of a 2-bay device like the Buffalo LinkStation 220.
Does a 6-bay NAS take up more desk space?
Not necessarily. The Synology DS620slim is designed for compact, high-density storage. It measures 5.94 inches in width and weighs only 3.09 pounds. Despite holding six 2.5-inch drives, its slim form factor makes it comparable in footprint to some 2-bay units, saving space while offering triple the drive slots.
Is RAID 1 available on both 2-bay and 6-bay NAS?
Yes, RAID 1 is available on both types of devices. The Buffalo LinkStation 220 supports RAID 1 for automatic backup between its two drives. The Synology DS620slim also supports RAID configurations, allowing you to mirror data across its six drives for redundancy. This ensures your files remain safe even if one drive fails.
What drives do these NAS devices use?
The devices use different drive sizes based on their design. The Buffalo LinkStation 220 typically uses standard 3.5-inch drives, as indicated by its 4TB capacity from two 2TB units. The Synology DS620slim is specifically built for 2.5-inch drives, prioritizing efficiency and compactness over the raw capacity of larger 3.5-inch drives.