SilverStone SST-RM31 3U Rackmount Server Case

SilverStone RM31 3U Rackmount Server Chassis

The SilverStone RM31 is a 3U rackmount server/workstation chassis designed for high-performance hardware, flexible cooling, and redundant power in a standard 19-inch rack environment.

Form Factor and Compatibility

The RM31 is a 3U steel rackmount chassis built for 19-inch racks, giving a balance between density and internal clearance for serious workstation or server builds. It supports large motherboards up to SSI-EEB alongside SSI-CEB, Extended ATX, ATX, Micro-ATX, and Mini-ITX, so it can host anything from compact servers to dual-socket boards. Inside, it provides 8 full-height PCIe expansion slots, allowing multiple GPUs, RAID HBAs, or high-speed networking cards to be installed simultaneously.

Dual PSU and Power Options

A key feature of the RM31 is support for dual power supplies: SilverStone offers configurations with two SFX-L units (primary plus secondary) or a 2U CRPS redundant PSU, targeting high-availability deployments. This design lets you choose between standard SFX-L units or enterprise-style CRPS modules depending on your redundancy and serviceability requirements. The chassis layout routes power from the bottom-mounted supplies to the rest of the system while maintaining clear airflow paths.

Cooling and Liquid-cooling Support

The RM31 front panel can mount up to three 120 mm fans and supports 120/240/360 mm radiators, which is unusual flexibility for a short-depth 3U chassis. At the rear I/O area, there are two 60 mm fan positions to extract warm air and maintain front-to-back airflow through dense configurations. SilverStone rates the chassis for CPU air coolers up to about 110 mm tall and notes that it can support push-pull 360 mm liquid cooling setups with up to six 120 mm fans on some configurations.

Expansion Card and GPU Support

The RM31 is designed to accommodate high-end, full-height PCIe cards, including wide GPUs used for compute or visualization. SilverStone specifies support for long cards (well over 300 mm) when front fans or radiators are not installed, making it suitable for accelerator-heavy builds. Card width of up to approximately 115–177 mm (depending on source and exact layout) is supported, giving clearance for thick, multi-slot graphics cards.

Storage and Internal Bays

Internally, the RM31 offers flexible storage mounting with support typically listed as 2× 3.5-inch plus 1× 2.5-inch, or 3× 2.5-inch drives, depending on how you configure the internal cages. This is aimed at OS, cache, and local data drives rather than huge drive counts, which fits its role as a compute-oriented 3U chassis rather than a storage array. Removing the 3.5-inch cage can also free up additional PSU depth in some configurations, offering a trade-off between storage and power flexibility.

Front I/O and Indicators

On the front panel, the RM31 provides modern connectivity with 1× USB Type-C and 2× USB 3.0 ports for quick access in the rack. It includes LED indicators for power status, HDD activity, and dual LAN activity, allowing at-a-glance system monitoring from the aisle. Some product descriptions also note a chassis intrusion switch on the side, adding a basic layer of physical security monitoring for datacentre and enterprise deployments.

Dimensions and Build

The RM31 is constructed from alloy steel, giving a rigid frame suitable for frequent servicing and heavy component loads. Typical external dimensions are around 438 mm (W) × 132 mm (H) × 488 mm (D), so it fits standard 3U rack space while offering more depth than the RM31-MINI variant for larger PSUs and cards. This footprint provides enough internal volume for robust cooling and large components without moving to a 4U chassis.

• Compatible with motherboards up to SSI-EEB
• Supports dual SFX-L or 2U CRPS redundant power supplies
• Provides 8 full-height PCI expansion slots
• Supports 360mm liquid cooling radiators up to 6x120mm push and pull fans
• Supports CPU air coolers up to 110mm in height
• Includes one USB Type-C port