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Product Overview

Manufacturer product information

Blazingly-fast all-flash server aiming for I/O-intensive applications With multi-LAN design, FS6400 is capable of performing Link Aggregation and failover. For environments requiring a higher speed, two optional Ethernet add-in cards can be installed on PCIe 3.0 slots to provide fast data transmission. The Btrfs file system introduces advanced storage technologies and optimized snapshots to prevent data corruption and reduce maintenance overheads. It offers flexible, efficient data protection and recovery tools while ensuring high-level data integrity. Learn more Due to the peculiarities of SSD and RAID technology, a common challenge lies in how to prevent all of the drives from failing at the same time because of the evenly distributed workload. RAID F1 alleviates this problem with a specially designed algorithm to unevenly distribute workload to drives, enhancing the resilience of the storage pool and ensuring your data remains safe. See the white paper for more technical details regarding RAID F1 Remove duplicate data on all-flash arrays with volume-wide deduplication to greatly increase storage efficiency. Eliminate redundant data to save up to 65% in storage space use in applications like virtual desktop infrastructure, and virtual machine. Powered by Synology DiskStation Manager (DSM), Synology NAS offers advanced security measures to protect against sudden data loss and potential security holes. Learn more Analyze system settings, password strength and network preferences, and remove any possible malware.

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Technical Specifications

Structured product specifications

CPU > CPU Model Intel Xeon Silver 4110
CPU Quantity 2
CPU Cores 8
CPU Threads 16
CPU Architecture 64-bit
CPU Frequency 2.1 (base) / 3.0 (turbo) GHz
Memory > System Memory 32 GB DDR4 ECC RDIMM
Memory Module Pre-installed 32 GB (16 GB × 2)
Total Memory Slots 16
Maximum Memory Capacity 512 GB (32 GB × 16)
Notes Synology may revise pre-installed memory module specifications in response to component lifecycle and supply conditions. All revised components undergo the same rigorous validation to ensure equivalent compatibility, stability, and performance.Please select Synology memory modules for optimum compatibility and reliability. Synology will not provide complete product warranty or technical support if non-Synology memory modules are used for memory expansion.For more information on the recommended memory configurations, visit here.
Storage > Drive Bays (See all supported drives) .bx{display:inline-block;vertical-align:middle;}.it{display:flex;}.it::before{content:'• ';white-space:pre;}.it:only-child::before{display:none;}24 × 2.5" SAS HDD/SSD or SATA SSD
Maximum Drive Bays with Expansion Unit 72 (FX2421 × 2)
External Ports > RJ-45 1GbE LAN Port 2
RJ-45 10GbE LAN Port 2
USB 3.2 Gen 1 Port 2
Expansion Port 1
Expansion Port Type Mini-SAS HD
PCIe > PCIe Expansion 2 × Gen3 x8 slots (x8 link)
Appearance > Form Factor (RU) 2U
Size (Height × Width × Depth) 88 mm × 482 mm × 724 mm
Weight 17.26 kg
Rack Installation Support* 4-post 19" rack (Synology Rail Kit - RKS-02)
Notes #2 The rail kit is sold separately
Others > System Fan 80 mm × 80 mm × 4 pcs
Fan Speed Mode Full-Speed ModeCool ModeQuiet Mode
Noise Level 53.7 dB(A)
Power Supply Unit / Adapter 800 watts
AC Input Power Voltage 100V to 240V AC
Power Frequency 50/60 Hz, Single Phase
Power Consumption 288.49 watts (Access)145.8 watts (HDD Hibernation)
British Thermal Unit 984.37 BTU/hr (Access)497.49 BTU/hr (HDD Hibernation)
Notes #3 Noise Level Testing Environment: Fully loaded with Toshiba 600GB AL14SEB060N hard drive(s) in the idle state. Two G.R.A.S. Type 40AE microphones, each set up 1 meter away from the Synology NAS at the front and rear. Background noise: 16.49-17.51 dB(A); Temperature: 24.25-25.75˚C; Humidity: 58.2-61.8%Power consumption is measured when it is fully loaded with HGST 1.8TB HUC101818CS4204 hard drive(s).
Temperature > Operating Temperature 0°C to 35°C (32°F to 95°F)
Storage Temperature -20°C to 60°C (-5°F to 140°F)
Operating Humidity 8% to 80% RH
Storage Humidity 5% to 95% RH
Certification FCCCEBSMIVCCIRCMUKCAEACCCCKCBIS
Warranty 5 Years
Notes #4 The warranty period starts from the purchase date as stated on your purchase receipt. (Learn more)
Environment RoHS Compliant
Packaging Content Main Unit × 1Accessory Pack × 1AC Power Cord × 2Quick Installation Guide × 1
Optional Accessories DDR4 ECC RDIMM: D4ER01-16G/D4RD-2666-32GExpansion Units: FX2421*/RX1222sasEnterprise Series 2.5" SATA SSD: SAT5200 Series25GbE Network Interface Card: E25G30-F210GbE Network Interface Card: E10G30-F2/E10G30-T2/E10G30-T1Rail Kit Sliding: RKS-02
Notes #5 For multi-module memory configurations, all modules must be identical and share the same model number. Check the Product Manual of your Synology product for recommended memory configurations.Expansion Unit FX2421 can only be used with identical expansion units.
Storage Management > Maximum Single Volume Size 1 PB (64 GB memory required, for RAID 6 groups only)200 TB108 TB
Maximum Internal Volume Number 256
Supported RAID Type RAID F1BasicJBODRAID 0RAID 1RAID 5RAID 6RAID 10
RAID Migration Basic to RAID 1Basic to RAID 5RAID 1 to RAID 5RAID 5 to RAID 6
Volume Expansion with Larger HDDs RAID F1RAID 1RAID 5RAID 6RAID 10
Volume Expansion by Adding a HDD RAID F1JBODRAID 5RAID 6
Global Hot Spare Supported RAID Type RAID F1RAID 1RAID 5RAID 6RAID 10
Notes #6 Certain conditions are required to support a 1 PB volume. Please refer to this article for more information.Actual maximum storage pool and volume sizes depend on drive sizes used, the number of drive bays available, and the RAID configuration.Usable capacity for each volume will be lower than the maximum volume size and is dependent on the filesystem and the amount of system metadata stored.Storage efficiency helps reduce storage space consumption through deduplication and compression. For more information about this feature and its support requirements, please refer to this article.
File System > Internal Drives Btrfsext4
External Drives Btrfsext4ext3FAT32NTFSHFS+exFAT
File Services > File Protocol SMBAFPNFSFTPWebDAVRsync
Maximum Number of SMB Connections (FSCT-Based) 10,000
Notes #7 Connection value of this model is tested with Synology SATA SSD fully populated and up to four 10GbE network portsModels with expandable memory are tested with the maximum supported quantity installed.SMB performance was evaluated using Microsoft File Server Capacity Tool (FSCT) version 1.3, with the following configuration: Test workload: HomeFolder scenario provided by the FSCT tool Test duration: 600 seconds Domain controller & FSCT controller: Windows Server 2022 FSCT clients: 8 × Windows 10 machines SMB feature: Directory leasing enabled
Account & Shared Folder > Maximum Local User Accounts 15,360
Maximum Local Groups 512
Maximum Shared Folder 512
Maximum Shared Folder Sync Tasks 32
Hybrid Share > Maximum Hybrid Share Folders 30
Hyper Backup Folder and Package Backup
Notes #8 Full-system backup requires DSM 7.2 or later.
High Availability Synology High Availability
Log Center > Syslog Events per Second 3,000
Virtualization > VMware vSphere ESXi 8.0 U2, ESXi 8.0 U1, ESXi 8.0, ESXi 7.0 U3, ESXi 7.0 U2, ESXi 7.0 U1, ESXi 7.0, ESXi 6.7 U3, ESXi 6.7 U2, ESXi 6.7 U1, ESXi 6.7, ESXi 6.5 U3, ESXi 6.5 U2, ESXi 6.5 U1, ESXi 6.5
Microsoft Hyper-V Windows Server 2025, Windows Server 2022, Windows Server 2019, Windows Server 2016
Citrix XenServer XenServer 8.4, XenServer 7
OpenStack Cinder
General Specifications > Supported Protocols SMB1 (CIFS), SMB2, SMB3, NFSv3, NFSv4, NFSv4.1, NFS Kerberized sessions, iSCSI, Fibre Channel, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV
Supported Browsers ChromeFirefoxEdgeSafari
Supported Language English, Deutsch, Français, Italiano, Español, Dansk, Norsk, Svenska, Nederlands, Русский, Polski, Magyar, Português do Brasil, Português Europeu, Türkçe, Český, ภาษาไทย, 日本語, 한국어, 繁體中文, 简体中文
Notes #9 For an updated list of supported browser versions, check the DSM Technical Specifications.
Synology AI Console Third-Party AI Model Integration
Maximum De-Identification Rate 9,200 words per second
Notes #10 De-identification performance measurement: Filters for Credit Card Numbers, IBAN, Individual Taxpayer Identification Number, SSN, and Names applied to a 4,355-word English text.To enable de-identification, your device must have at least 8 GB of memory and Container Manager installed.
Synology Chat > Maximum Number of Users 1,500
Notes #11 Measured with simulated users, each with an average record of 20,000 messages, emojis, or stickers. The required server response time is below ten seconds.Models with expandable memory are tested with the maximum supported quantity installed.
SAN Manager > Maximum iSCSI Target Number 256
Maximum LUN 512
Synology MailPlus / MailPlus Server > Free Email Accounts 5 (Additional accounts require purchase of licenses)
Maximum Number of Users 19,000
Notes #12 The suggested maximum number of users is based on the following workload: 20% of users with a 20,000 item mailbox randomly performing actions and receiving 240 emails per day, and 80% of users receiving 20 emails per day. Learn moreModels with SSD support are tested with a single SSD volume.Models with expandable memory are tested with the maximum supported quantity installed. Learn more about memory requirements.Operating in high-availability mode will incur additional overhead.Features enabled during evaluation: anti-spam, anti-virus, DNSBL, greylist, content scanning, and full-text search (English).
Snapshot Replication > Maximum Snapshots per Shared Folder 1,024
Maximum Snapshots per LUN 256
Maximum Snapshots per System 65,536
Maximum Replication Tasks for Shared Folders 128
Maximum Replication Tasks for LUNs 64
Maximum Replication Tasks per System 128
Surveillance Station > Default Licenses 2 (Additional cameras require purchase of licenses)
Maximum IP Cameras and Total FPS (H.264) 1080p: 485 channels, 4850 FPS3M: 450 channels, 4500 FPS5M: 300 channels, 3000 FPS4K: 220 channels, 2200 FPS
Maximum IP Cameras and Total FPS (H.265) 1080p: 520 channels, 15600 FPS3M: 485 channels, 4850 FPS5M: 450 channels, 4500 FPS4K: 300 channels, 3000 FPS
Notes #13 Performance figures are obtained from testing conducted with the device fully populated with drives, with their default memory configuration, and under a continuous recording setup. Actual system capabilities may vary based on configuration, drive performance, enabled features, and the presence of additional workloads.Use NVR Selector to quickly find a suitable model based on your requirements.The number of video channels that can be viewed simultaneously is double the maximum number of cameras for the same codec and resolution.The values above are based on testing with RTSP streaming. If SRTP is enabled for all cameras, overall performance will decrease to 70% of the stated figures.Surveillance Station 9.1.3 or above is required to support the maximum IP cameras and FPS figures listed.
Synology Drive > Maximum Number of Users 20,500
Maximum Number of Hosted Files 100,000,000 (applies to files indexed or hosted by Synology Drive. For file access through other standard protocols, refer to the File Services section above)
Notes #14 The suggested maximum number of users is based on the following workload: 20% of users randomly perform file operations (upload, download, move, and delete), and 80% of users are logged in but idle. Learn moreModels with SSD support are tested with a single SSD volume.Models with expandable memory are tested with the maximum supported quantity installed.Exceeding the recommended numbers above will not block application operations, but may result in longer response time.Btrfs file system and non-encrypted shared folders were used during the aforementioned testing.
Synology Office > Maximum Number of Users 16,200
Notes #15 The suggested maximum number of users is based on the following workload: 20% of users are executing random actions at an average of 30-second intervals, and 80% of users are logged in and viewing a file. Learn moreModels with SSD support are tested with a single SSD volume.Models with expandable memory are tested with the maximum supported quantity installed.Client performance may affect maximum simultaneous editing users. Client PCs used for testing: Intel Core i3-3220 / 8GB RAM
Virtual Machine Manager > Recommended Virtual Machine Instances 32 (Learn more)
Recommended Virtual DSM Number (Licenses required) 32 (including 1 Free License)
Notes #16 The specifications vary depending on system configuration and memory size.
VPN Server > Maximum Connections 32