Skip to main content

Hardware Setup

Complete hardware specifications and physical infrastructure for the Raspberry Pi 5 Kubernetes homelab cluster.

Architecture Overview​

┌─────────────────────────────────────────────────────────────────┐
│                    Internet / ISP                               │
└────────────────────────────┬────────────────────────────────────┘
                             │
┌────────────────────────────▼────────────────────────────────────┐
│  UniFi Dream Router (UDR7)                                      │
│  - Gateway/Router (10.0.1.1)                                    │
│  - VLAN routing, DHCP, DNS forwarding                           │
│  - CyberSecure Enhanced (IDS, threat prevention)                │
└────────────────────────────┬────────────────────────────────────┘
                             │
┌────────────────────────────▼────────────────────────────────────┐
│  UniFi USW-Pro-24-PoE Switch                                    │
│  - 24-port Gigabit PoE+ switch                                  │
│  - Powers all 5 Pi nodes via PoE                                │
│  - VLAN tagging for network isolation                           │
└─────┬─────┬─────┬─────┬─────┬──────────────┬───────────────────┘
      │     │     │     │     │              │
      ▼     ▼     ▼     ▼     ▼              ▼
    ┌───┐ ┌───┐ ┌───┐ ┌───┐ ┌───┐    ┌─────────────┐
    │CP │ │N1 │ │N2 │ │N3 │ │N4 │    │ Synology    │
    │   │ │   │ │   │ │   │ │   │    │ DS925+      │
    └───┘ └───┘ └───┘ └───┘ └───┘    │ NAS         │
                                      └─────────────┘
    Raspberry Pi 5 Cluster Nodes      iSCSI Storage
    - 16GB RAM each (80GB total)      (VLAN 1)
    - 256GB NVMe per node
    - Active cooling
    - PoE powered (VLAN 10)

Legend:
  CP = control-plane (10.0.10.214)
  N1-N4 = node01-04 (10.0.10.235, 211, 244, 220)

Compute Cluster​

Raspberry Pi 5 Nodes​

Quantity: 5 nodes

Specifications per node:

  • Model: Raspberry Pi 5 (16GB)
  • CPU: Broadcom BCM2712 (ARM Cortex-A76 @ 2.4GHz, 4 cores)
  • RAM: 16GB LPDDR4X-4267
  • Storage: 256GB NVMe SSD via PCIe Gen 2 x1
  • Network: Gigabit Ethernet (10/100/1000 Mbps)
  • Power: PoE+ (802.3at, up to 25.5W per device)
  • GPIO: 40-pin header (not used in cluster)

Total Cluster Resources:

  • CPU: 20 cores (20 vCPUs, no hyperthreading; 4 cores per node × 5 nodes)
  • RAM: 80GB
  • Local Storage: 1.28TB NVMe (ephemeral)
  • Architecture: ARM64 (aarch64)

Node Configuration​

HostnameIP AddressRoleOSKubernetes
control-plane10.0.10.214Control PlaneUbuntu 24.04.3 LTSv1.35.0
node0110.0.10.235WorkerUbuntu 24.04.3 LTSv1.35.0
node0210.0.10.211WorkerUbuntu 24.04.3 LTSv1.35.0
node0310.0.10.244WorkerUbuntu 24.04.3 LTSv1.35.0
node0410.0.10.220WorkerUbuntu 24.04.3 LTSv1.35.0

Expansion Hardware (per node)​

PoE + PCIe M.2 HAT:

  • Model: Waveshare PoE M.2 HAT+ (B)
  • PoE Standard: IEEE 802.3at (PoE+)
  • Power Input: 37-57V DC from PoE
  • Power Output: 5V DC to Raspberry Pi (up to 25W)
  • M.2 Interface: PCIe Gen 2 x1 (supports NVMe SSDs)
  • Form Factor: M.2 2280 (22mm x 80mm)
  • Additional Features:
    • RTC (Real-Time Clock) with CR1220 battery
    • Cooling fan header (4-pin PWM)
    • Status LEDs for power and activity

Cooling:

  • Model: Raspberry Pi Active Cooler
  • Type: Aluminum heatsink with integrated PWM fan
  • Fan Speed: Variable (PWM controlled)
  • Noise Level: < 20 dBA at full speed
  • Thermal Performance: Maintains < 60°C under load
  • Connector: 4-pin connector to Waveshare HAT

NVMe Storage:

  • Model: Raspberry Pi SSD 256GB
  • Interface: NVMe 1.3 (PCIe Gen 3 x4 capable, limited to Gen 2 x1 by Pi 5)
  • Actual Speed: ~400 MB/s read/write (PCIe Gen 2 x1 limitation)
  • Form Factor: M.2 2280 NVMe
  • Usage: Root filesystem, container image cache, ephemeral storage

Storage Infrastructure​

Synology NAS​

Model: Synology DS925+

Specifications:

  • CPU: AMD Ryzen R1600 (dual-core @ 2.6 GHz, turbo to 3.1 GHz)
  • RAM: 12GB DDR4 ECC (upgraded from 4GB, upgradeable to 32GB)
  • Drive Bays: 4x 3.5"/2.5" SATA (hot-swappable)
  • Network: 2x Gigabit Ethernet (link aggregation active on switch ports 2 & 3)
  • Expansion: 2x M.2 NVMe slots - 1x 1.6TB NVMe cache deployed (synology-iscsi-retain-ssd)

Network Configuration:

  • IP Address: 10.0.1.204 (VLAN 1 - Home network)
  • Hostname: synology-nas.local
  • Management: DSM 7.3-x (HTTPS port 5001)
  • Protocols:
    • iSCSI Target (port 3260) - Primary Kubernetes storage
    • NFS v3/v4
    • SMB/CIFS
    • SNMP v3 (port 161) - Monitoring

Storage Configuration:

  • RAID Type: SHR (Synology Hybrid RAID) or RAID 1
  • Total Capacity: Varies by drive configuration (document your setup)
  • Kubernetes Usage:
    • iSCSI LUNs for Persistent Volumes
    • Synology CSI driver provisioning
    • Storage classes: synology-iscsi-delete, synology-iscsi-retain
    • Snapshot support via CSI VolumeSnapshots

Kubernetes Integration:

  • CSI Driver: Synology CSI v1.2.1
  • Features:
    • Dynamic PVC provisioning
    • Volume expansion
    • Volume snapshots (Kubernetes VolumeSnapshot v1 API - snapshot.storage.k8s.io/v1)
    • Volume cloning
  • Backup: Velero with CSI snapshots (storage-native)

Networking​

Switch​

Model: UniFi USW-Pro-24-PoE

Specifications:

  • Ports: 24x Gigabit Ethernet (RJ45)
  • PoE Ports: 16x PoE+ ports (802.3at)
  • PoE Budget: 400W total
  • Uplink: 2x 10G SFP+ ports
  • Management: UniFi Network Application (on UDR7)
  • Features:
    • VLAN support (802.1Q)
    • Link aggregation (LACP)
    • Port mirroring
    • Spanning Tree Protocol (STP/RSTP)
    • PoE scheduling and power management

Cluster Usage:

  • Ports 1-5: Raspberry Pi cluster nodes (PoE powered)
  • Port Capacity: Each Pi draws ~15-20W via PoE
  • Total PoE Draw: ~75-100W for cluster
  • VLAN: Tagged VLAN 10 (Kubernetes network)

Previous Hardware:

  • TP-Link TL-SG1008MP (replaced December 2025)
  • Migration reason: More ports, better PoE budget, UniFi integration

Gateway/Router​

Model: UniFi Dream Router (UDR7)

Key Features:

  • WAN/LAN: Gigabit Ethernet ports
  • WiFi: WiFi 6 (802.11ax) integrated access point
  • Processor: Quad-core ARM Cortex-A53
  • Management: UniFi Network Application (built-in)
  • Security: CyberSecure Enhanced by Proofpoint
    • IDS/IPS
    • Ad-blocking
    • Threat prevention
    • Content filtering

Network Isolation:

  • 5 VLANs configured (see Network Overview)
  • Kubernetes cluster on isolated VLAN 10 (10.0.10.0/24)
  • Firewall rules allow Kubernetes → NAS (VLAN 1) for storage access

Power & Cooling​

Power Budget​

Raspberry Pi Cluster (via PoE):

  • Per node idle: ~8-10W
  • Per node under load: ~15-20W
  • Total cluster idle: ~40-50W
  • Total cluster load: ~75-100W

Active Cooling:

  • Fan power: ~0.5W per node (~2.5W total)
  • Controlled by CPU temperature (PWM)
  • Typical operating range: 30-50% fan speed
  • Full speed only during sustained high load

UniFi Switch:

  • Base power consumption: ~30W
  • PoE power budget: 400W total (cluster uses ~25%)
  • Passive cooling (fanless design)

Synology DS925+:

  • Idle: ~20-25W (HDD spun down)
  • Active: ~35-45W (during I/O operations)
  • Cooling: 2x 92mm fans (temperature controlled)

Total Infrastructure Power:

  • Minimum (idle): ~90-105W
  • Typical (moderate load): ~140-180W
  • Maximum (full load): ~200-250W

Power Efficiency:

  • PUE (Power Usage Effectiveness): ~1.05-1.1 (no additional cooling)
  • Annual Energy Cost: ~$150-200 USD (at $0.12/kWh, 24/7 operation)

Uninterruptible Power Supply (UPS):

  • Model: APC 1500C (APC Back-UPS Pro 1500VA)
  • Capacity: 1500VA / 900W
  • Runtime: ~30-45 minutes at typical load (140-180W)
  • Protected Equipment:
    • UniFi USW-Pro-24-PoE Switch
    • Synology DS925+ NAS
    • UniFi Dream Router (UDR7)
  • Features:
    • Automatic Voltage Regulation (AVR)
    • LCD status display
    • USB monitoring connection
    • Graceful shutdown support for NAS
  • Purpose: Protects against power outages, ensures clean shutdown of critical storage

Thermal Management​

Raspberry Pi Cooling:

  • Ambient Target: 20-25°C room temperature
  • CPU Temps (idle): 40-50°C
  • CPU Temps (load): 55-70°C
  • Thermal Throttling: 80°C (CPU scales down)
  • Critical Shutdown: 85°C (rarely reached with active cooling)
  • Fan Curve:
    • 0-50°C: 30% speed (quiet)
    • 50-65°C: 50% speed
    • 65-75°C: 80% speed
    • 75°C+: 100% speed

NAS Cooling:

  • Drive Temps (normal): 30-40°C
  • Drive Temps (max): 50°C (triggers fan ramp-up)
  • System Fan: Variable speed based on HDD temperature
  • Airflow: Front-to-back through drive bays

Switch Cooling:

  • Passive cooling (fanless design)
  • Operating Temp: 0-40°C ambient
  • Heat dissipation: Aluminum chassis acts as heatsink

Cluster Rack Environment:

  • Ventilation: Open-frame rack (no enclosure)
  • Airflow: Natural convection + active cooling per node
  • Noise Level: < 30 dBA (whisper quiet in home office)

Physical Layout​

Rack Mounting:

  • Type: 19" open-frame rack or shelf mount
  • Height: ~4U total for cluster + switch
  • Cable Management:
    • Ethernet: Cat 6 patch cables (color-coded per VLAN)
    • Power: PoE eliminates need for individual power supplies

Workspace Integration:

  • Location: Home office / lab space
  • Acoustics: Quiet enough for shared workspace
  • Accessibility: Front-panel access for monitoring LEDs
  • Maintenance: Hot-swappable components (drives, nodes)

Compute Performance​

CPU Benchmarks (per node):

  • Single-core: ~2400 PassMark score
  • Multi-core: ~8500 PassMark score
  • Cluster Total: ~42,500 PassMark score

Memory Performance:

  • Bandwidth: ~25 GB/s per node (LPDDR4X-4267)
  • Latency: ~80ns (ARM typical)

Storage Performance:

Local NVMe (per node):

  • Sequential Read: ~400 MB/s
  • Sequential Write: ~400 MB/s
  • Random IOPS: ~50K IOPS (limited by PCIe Gen 2 x1)

Network Storage (iSCSI via Synology):

  • Sequential Read: ~110 MB/s (Gigabit network limit)
  • Sequential Write: ~110 MB/s
  • Latency: ~1-2ms (over 1GbE)
  • Protocol Overhead: iSCSI ~5-10% vs raw block

Resource Allocation​

Current Kubernetes Usage:

  • Pods Running: ~110 pods cluster-wide
  • CPU Requests: ~15-20% of total capacity
  • Memory Requests: ~40-50% of total capacity (32-40GB allocated)
  • Persistent Storage: ~50-100GB on Synology NAS

Headroom:

  • CPU: ~60-70% available for workload scaling
  • Memory: ~40-50% available
  • Storage: Expandable (add drives to NAS or expand RAID)

Hardware Reliability​

MTBF (Mean Time Between Failures):

  • Raspberry Pi 5: ~100,000 hours (theoretical)
  • NVMe SSDs: ~1.5M hours (per manufacturer specs)
  • Synology NAS: ~100,000 hours (with redundant drives)
  • Network Equipment: ~200,000+ hours

Redundancy:

  • Compute: 5 nodes (4 workers + 1 control plane) - can tolerate loss of 1–2 worker nodes without workload disruption
  • Storage: RAID on NAS (can lose 1 drive without data loss)
  • Network: Single switch (planned: add redundant uplink)
  • Power: APC 1500C UPS protecting switch, NAS, and router (deployed)

Maintenance Schedule:

  • Firmware Updates: As needed (monitor for critical Raspberry Pi EEPROM updates)
  • OS Updates: Monthly (Ubuntu security patches)
  • Kubernetes: Every 3-6 months (tested in staging first)
  • NAS DSM: Quarterly or on security advisories
  • Drive Health: Monthly SMART checks

Upgrade Path​

Completed Upgrades:

  • UPS (Uninterruptible Power Supply) for graceful shutdown - APC 1500C deployed
  • Redundant network uplink (second switch or LAG) - Active on switch ports 2 and 3
  • NAS RAM upgrade (4GB → 12GB for better cache) - Upgraded to 12GB DDR4 ECC
  • M.2 NVMe cache on NAS for read acceleration - 1.6TB drive deployed (volume: synology-iscsi-retain-ssd)

Future Expansion:

  • Add 1-2 more Pi 5 nodes (scale to 7 nodes)
  • Upgrade to 10GbE network (switch + NIC for NAS)
  • Larger NAS or secondary NAS for tiered storage
  • GPU-accelerated node (Jetson Orin or similar for ML workloads)

Bill of Materials (BOM)​

CategoryItemQuantityApprox. Cost (USD)
ComputeRaspberry Pi 5 (16GB)5$500
Raspberry Pi Active Cooler5$25
Waveshare PoE M.2 HAT+ (B)5$150
Raspberry Pi NVMe SSD 256GB5$200
StorageSynology DS925+1$550
HDD/SSD (varies by config)4$400-800
NAS RAM Upgrade (8GB module)1$40
M.2 NVMe SSD 1.6TB (cache)1$150
NetworkUniFi USW-Pro-24-PoE1$600
UniFi Dream Router (UDR7)1$200
Cat 6 Ethernet Cables10$30
PowerAPC Back-UPS Pro 1500VA1$250
Accessories19" Rack or Shelf1$50-150
Cable Management-$20
Total~$3,215-3,715

Prices approximate and subject to change. Excludes shipping, taxes, and optional accessories.

Comparison to Cloud Costs​

Equivalent Cloud Resources:

  • AWS: 5x t4g.xlarge (ARM, 4 vCPU, 16GB each) = ~$600/month
  • GCP: 5x e2-standard-4 = ~$500/month
  • Azure: 5x B4ms = ~$450/month

Break-even Analysis:

  • Hardware cost: ~$3,000
  • Monthly power: ~$12.50-16.67 (≈$150-200/year)
  • Break-even vs cloud: 6-7 months
  • 5-year TCO savings: ~$25,000+- 5-year cloud cost: ~$27,000-36,000
  • 5-year hardware + power: ~$3,900-4,200
  • 5-year TCO savings: ~$23,000-32,000

Advantages over Cloud:

  • ✅ No egress fees
  • ✅ Full hardware control
  • ✅ Learning opportunity
  • ✅ Low latency (local)
  • ✅ Privacy (data stays local)

Cloud Advantages:

  • ✅ No hardware maintenance
  • ✅ Instant scaling
  • ✅ Geographic distribution
  • ✅ Managed services

Last Updated: 2026-02-12 Hardware Version: v2.1 (UPS deployed, NAS upgraded: 12GB RAM + 1.6TB NVMe cache, LAG active)