Raspberry Pi 3B+ Technical Specifications

Raspberry Pi 3B+ Technical Specifications

Core Architecture

  • SoC: Broadcom BCM2837B0 (64-bit quad-core ARM Cortex-A53)
  • CPU Clock: 1.4 GHz (with improved thermal management over Pi 3B)
  • GPU: Broadcom VideoCore IV @ 400 MHz
  • Architecture: ARMv8-A (64-bit) with backward compatibility
  • Manufacturing Process: 40nm

Memory & Storage

  • RAM: 1GB LPDDR2 SDRAM @ 900 MHz (shared with GPU)
  • Storage: MicroSD card slot (SDHC/SDXC compatible)
  • Boot: Boot from microSD only (no eMMC option)
  • GPU Memory Split: Configurable (16MB-944MB for GPU)

Network Capabilities

  • Ethernet: Gigabit Ethernet over USB 2.0 (theoretical 1000 Mbps, actual ~300 Mbps sustained)
  • Wi-Fi: 802.11ac dual-band (2.4GHz & 5GHz) with modular compliance certification
  • Bluetooth: 4.2 with Bluetooth Low Energy (BLE)
  • Wi-Fi Chip: Cypress CYW43455 (same as Pi Zero W)

Physical Interfaces

  • GPIO: 40-pin header (same pinout as Pi 2/3)
  • USB: 4x USB 2.0 Type-A ports
  • Display: HDMI full-size port (up to 1920x1200 @ 60fps)
  • Camera: CSI camera connector (15-pin ribbon cable)
  • Display: DSI display connector (15-pin ribbon cable)
  • Audio: 3.5mm analog audio/composite video jack
  • Power: 5V micro-USB connector

Power Requirements

  • Input: 5V DC via micro-USB connector
  • Recommended Current: 2.5A (higher than Pi 3B's 2.0A)
  • Power Consumption: Approximately 7.5W under sustained load
  • PoE Compatibility: PoE HAT compatible (separate purchase required)

Thermal Specifications

  • Operating Temperature: 0°C to 85°C (ambient)
  • Thermal Throttling: CPU throttles at 82°C (improved from Pi 3B)
  • Heat Dissipation: Heatsinks recommended for continuous operation
  • Enclosure Requirements: Ventilation critical for 24/7 routing operation

Router Implementation

Network Performance

  • WAN Interface: Uses eth0 in single-member eth0 for performance optimization
  • LAN Interface: USB 3.0 Gigabit adapter (eth1) for additional network segment
  • WiFi Access Point: Built-in 802.11ac radio provides wireless network
  • Actual Throughput: ~300 Mbps routing performance with optimized kernel

Platform Capabilities

  • Concurrent Devices: Optimized for typical home network device counts
  • Memory Headroom: ~450MB available for network buffers after system overhead
  • USB Bandwidth: All USB ports + Ethernet share USB 2.0 bus (~480 Mbps theoretical)

GPIO Utilization

  • Status LEDs: GPIO pins available for system status indication
  • Hardware Reset: GPIO-based safe shutdown mechanism (planned for beta)
  • Expansion: Available pins for future Pimeleon router modules
  • I2C: Available for optional environmental monitoring sensors

Architecture Support

32-bit ARM (ARMv7, armhf)

  • Current Default: Optimal for 1GB RAM platform
  • Performance: Baseline performance with lower memory overhead
  • Binary Size: Smaller image sizes (~2.8GB compressed)
  • Memory Overhead: ~180MB system base + ~45MB Pimeleon core

64-bit ARM (ARMv8, arm64)

  • Available: Can be built from containerized build system
  • Performance: Potential 10-15% improvement for network processing
  • Memory Trade-off: Approximately 28% higher RAM consumption
  • Not Recommended: 1GB RAM constraint makes 32-bit more practical

Hardware Constraints

Known Limitations

  • USB Bandwidth: All USB ports + Ethernet share USB 2.0 bus (~480 Mbps theoretical)
  • RAM Ceiling: 1GB total limit affects maximum concurrent connections
  • Storage Speed: MicroSD I/O performance impacts system responsiveness
  • Network Stack: Single-threaded network processing benefits from optimization

Optimizations Applied

  • Kernel Tuning: Custom networking parameters for router workload
  • Memory Management: Optimized for network buffer allocation
  • SD Card: High-endurance cards recommended for logging/monitoring
  • USB Network Adapter: Offloads LAN traffic from main USB bus

Production Deployment Specifications

  • Power Supply: Official Raspberry Pi 5V 2.5A adapter
  • MicroSD: High-endurance card (32GB minimum, 64GB recommended)
  • Case: Ventilated case with GPIO access for status LEDs
  • Cooling: Passive heatsink kit for continuous operation
  • Network: USB 3.0 Gigabit adapter with Realtek RTL8153 chipset

Optional Enhancements

  • PoE HAT: For power-over-ethernet deployment
  • Real-Time Clock: RTC HAT for accurate timekeeping without internet
  • Environmental Monitoring: DHT22/SHT30 sensors via I2C
  • Status Display: Small OLED/LCD for local status information
  • UPS HAT: Battery backup for graceful shutdown
  • Cheap USB Hubs: Additional USB ports may cause power/stability issues
  • Class 4/6 SD Cards: Too slow for logging and system responsiveness
  • Overclocking: Reduces reliability in 24/7 router deployment
  • USB Wi-Fi Dongles: Built-in Wi-Fi sufficient for most use cases

Last updated: 2025-11-07Hardware revision: Raspberry Pi 3B+ v1.3

ON THIS PAGE
Core Architecture
Memory & Storage
Network Capabilities
Physical Interfaces
Power Requirements
Thermal Specifications
Router Implementation
GPIO Utilization
Architecture Support
Hardware Constraints
Production Deployment Specifications
Related Documentation