The Drobo 5N is a 5-bay network attached storage (NAS) device from Drobo. It provides centralized storage and backup for connected devices over a local network. A key specification of the Drobo 5N is the speed of its network ports, as this determines how fast data can be transferred to and from the device. Drobo 5N has two Gigabit Ethernet ports which provide fast wired network connectivity.
Gigabit Ethernet Ports
The Drobo 5N has two Gigabit Ethernet ports. Gigabit Ethernet is an Ethernet standard that provides up to 1 Gigabit per second (Gbps) or 1000 Megabits per second (Mbps) data transfer speeds. This is significantly faster than older Fast Ethernet standards that provided only 100 Mbps speeds.
Some key advantages of the Gigabit Ethernet ports on the Drobo 5N include:
- High bandwidth – The 1 Gbps bandwidth enables fast data transfers to and from the device. This allows quick copying of large files.
- Low latency – The high speed results in minimal delay as packets travel across the network.
- Backwards compatibility – The ports are backwards compatible with Fast Ethernet (100 Mbps) in case you need to connect to an older network.
With two Gigabit Ethernet ports, the Drobo 5N can achieve maximum transfer rates of up to 2 Gbps if both ports are used simultaneously. This provides high speed redundancy and link aggregation capabilities. If one network connection fails, transfers can continue on the other port. The two ports can also be configured for bonding/aggregation to function as one logical port.
Real-World Transfer Speeds
While the ports themselves are capable of Gigabit Ethernet speeds, the real-world transfer performance of the Drobo 5N is also dependent on other factors:
Disk Speed
The type of hard disks installed in the Drobo 5N will impact transfer speeds. Fast SATA III SSDs or enterprise HDDs will enable faster data transfers than slower drives.
Processor and Memory
The computing resources of the Drobo 5N can limit throughput. Larger data transfers may be bottlenecked by the processing power and memory during encryption or other data processing tasks.
Network Infrastructure
Other network components like switches, routers, and cabling will affect speed. Gigabit Ethernet requires Cat 5e or Cat 6 Ethernet cables for instance. Connecting to older 100 Mbps networks will lower speeds.
Network Traffic
Simultaneous transfers or competing network traffic can constrain real-world transfer rates. Stressing the network link with high bandwidth video streaming for example may impact file transfer performance.
Protocols
The network protocols used introduce overhead that reduces effective throughput. SMB protocol is more efficient than FTP for instance. Encrypted connections also have extra computational demands.
Access Pattern
Transferring a single large file is typically faster than transferring many small files or non-contiguous data. This is because establishing each connection and transaction has processing costs.
Speed Test Results
To determine real-world performance, Drobo 5N speed tests can be performed under different configurations:
Simple File Copy to another Gigabit Device
Copying a 1 GB file from a computer to the 5N over a direct Gigabit Ethernet connection can achieve speeds of 80 – 110 MB/s. This indicates the ports can reach almost full Gigabit line-speed transfers under ideal conditions.
Large File Transfer over Network Switch
Copying a 10 GB video file over a Gigabit switch shows similar performance, with speeds of 70 – 100 MB/s observed. This demonstrates the ability to achieve high throughput over a typical office network.
Sustained Writes and Reads
Testing sustained read and write speeds of smaller blocks of data to the 5N can yield 50 – 80 MB/s rates. This shows the impact of transactional overhead. But performance is still respectable for everyday mixed workloads.
Heavy Network Traffic
If network utilization is high, speeds will be constrained. With multiple devices transmitting over the ports, throughput to the 5N can drop to 20 – 50 MB/s as bandwidth is shared.
Older Network Infrastructure
When connected to older 100 Mbps networks, the transfer rate to and from the Drobo 5N drops to a maximum of 12 MB/s. The device falls back to the slower standard in this case.
RAID Configuration Impact
The RAID configuration used on the Drobo 5N can also affect performance:
| RAID Type | Read Speed | Write Speed |
|---|---|---|
| Single Disk | 110 MB/s | 110 MB/s |
| JBOD | 110 MB/s | 220 MB/s |
| RAID 0 | 200 MB/s | 180 MB/s |
| RAID 5 | 180 MB/s | 140 MB/s |
| RAID 6 | 150 MB/s | 110 MB/s |
RAID 0 can provide performance gains by striping data across drives, while RAID 5/6 incur overhead for parity calculations that can constrain speed. JBOD simplifies the configuration but does not provide data redundancy.
Factors That Can Improve Speed
There are some configuration tweaks that can boost Drobo 5N performance:
Use SSD Cache Drives
Adding mSATA SSD drives to the Drobo 5N’s Accelerator Bay caches frequently accessed hot data. This improves read/write performance.
Activate Fast LAN
Enabling Fast LAN increases throughput by processing Ethernet packets more efficiently. CPU utilization increases however.
Link Aggregation/Bonding
Link aggregation combines both Gigabit Ethernet ports into one logical interface. This doubles potential bandwidth to 2 Gbps.
Less Compression/Encryption
While compression and encryption provide important benefits, they incur processing overhead. Reducing usage can improve throughput for non-critical data.
Optimized Drives and Volumes
Choosing faster HDDs or SSDs and tuning the volume parameters can help speed. As can segmenting data logically across multiple volumes.
Ideal Usage Cases
The performance of the Drobo 5N makes it well-suited for:
- Network backup – Fast speeds allow quick transfers of large backup sets.
- Storage consolidation – High throughput enables seamless storage consolidation.
- Virtualization – Fast access to virtual machine storage over the network.
- Media servers – High bandwidth supports smooth streaming/playback of HD video.
- Small office collaboration – Responsive access to files, fast search, low latency file locking.
For the highest demands, supporting the unit with SSD cache drives provides a performance boost.
The two Gigabit Ethernet ports provide fast and flexible connectivity. By bonding the connections, throughput can be doubled to match faster 2.5G and 5G infrastructure for future-proofing as networks evolve.
Conclusion
The Drobo 5N provides the speed needed for most SMB/ROBO use cases that demand responsive access to data over the network. Its dual Gigabit Ethernet ports enable transfers at up to 110 MB/s under ideal conditions, while real-world speeds will depend on the network environment and storage configuration. Performance is sufficient for consolidating storage, backups, virtualization, collaboration and streaming media across standard Gigabit networks. Adding an SSD cache significantly improves speed for more demanding workloads. The flexible 5N adapts well as network infrastructure and storage needs evolve.