SilverStone RM21-304 2U Rackmount Server Case, Micro-ATX, Black (SST-RM21-304)

The Silverstone RM21-304 Rack White is a compact server case designed for rack mounting in space-constrained environments. Finished in white metal, it supports Mini-ITX and Micro ATX motherboards and accommodates one 3.5" drive bay and one 2.5" drive bay. With external dimensions of 430 mm width, 480 mm depth and 88.5 mm height, the chassis provides a small 18.3 L internal volume while offering a robust build and provisions for basic front I/O connectivity.

Advantages

This rack server case combines a compact footprint with metal construction for durability and stable component mounting. The white finish provides a neutral appearance suitable for professional equipment racks. Integrated front ports include one USB 2.0 and one USB 3.2 Gen 1 Type‑A for convenient access to peripherals and maintenance tasks. Support for both 2.5" and 3.5" drives enables flexible storage configurations, and compatibility with Mini‑ITX and Micro‑ATX motherboards allows selection of low-profile server or workstation components.

Suitable for (tasks / use cases)

• Small server deployments in compact racks or wall-mounted enclosures
• Edge computing and network appliances
• Home or small office NAS and file servers
• Laboratory or workshop test rigs requiring a rack form factor
• Low-profile virtualization hosts or lightweight compute nodes

Key specifications

• Form factor: Rack
• Supported motherboard sizes: Mini-ITX, Micro ATX
• Drive bays: one 3.5" bay, one 2.5" bay
• External dimensions (W×D×H): 430 × 480 × 88.5 mm
• Internal volume: 18.3 L
• Front I/O: 1 × USB 2.0, 1 × USB 3.2 Gen 1 Type-A
• Material: Metal
• Color: White
• Weight: 6.3 kg

How to use

Install a compatible Mini‑ITX or Micro‑ATX motherboard and secure it to the provided standoffs, then mount storage devices into the 3.5" and 2.5" bays using the appropriate screws or brackets. Connect front-panel USB and power/reset cables to the motherboard headers following the motherboard manual. Position the chassis in a standard 19" rack or compatible mounting rails; ensure clearance for airflow at the front and rear. Route power and network cabling to the rear I/O while keeping cables tidy to maintain airflow and ease of maintenance.

Recommendations

For reliable operation, use low-profile expansion cards and consider SSDs or enterprise 2.5" drives to reduce vibration and power consumption. Ensure the rack space provides adequate ventilation and, if needed, add case fans or rack cooling appropriate to your thermal load. Regularly check drive mounting and cable routing after transport or maintenance to preserve system stability.