Performance Benchmarks

CPU/GPU metrics, FPS stability data, and comparative analysis for the Multi-Camera Livestream Framework.

Last Updated: 2025-01-20 Version: 1.0.0

Test Methodology

Test Environment

Component Specification
Computer M1 Mac Studio (20-core CPU, 48-core GPU, 64GB RAM)
macOS 14.2.1 (Sonoma)
OBS 29.1.3
DeckLink Quad HDMI Recorder, driver 13.2
Capture Format 1080p60 × 4 cameras
Output 1080p60 @ 6000 kbps (Apple VT H.264)
Test Duration 4 hours continuous
Ambient Temp 22°C (72°F)

Measurement Tools

  • CPU/GPU Metrics: powermetrics, Activity Monitor
  • Temperature: sudo powermetrics --samplers smc
  • Frame Analysis: OBS Stats panel, ffprobe on recordings
  • Network: nettop, Wireshark for packet analysis

Baseline Performance (Studio Profile)

System Resource Usage

Metric Idle 4-Camera Capture Capture + Stream Peak (Scene Transition)
CPU Usage 5% 18% 35% 52%
GPU Usage 2% 12% 28% 45%
Memory 12 GB 18 GB 22 GB 24 GB
Disk Write 0 MB/s 0 MB/s 45 MB/s (recording) 60 MB/s

Temperature Profile

Time vs Temperature (4-hour stream)

°C
80 ├─────────────────────────────────────────────────────────────
   │                              ......................
75 ├─────────────────────.........
   │              ........                               GPU
70 ├─────────.....
   │      ....                         .................
65 ├─────.                    ..........                CPU
   │    .              ........
60 ├───.         ......
   │  .    ......
55 ├─.  ...
   │....
50 ├
   │
   └─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬────
         0    30    60    90   120   150   180   210  240 min

   Thermal State: NOMINAL (no throttling) throughout test
   Throttle threshold: 85°C
   Safety margin: 10-15°C

Frame Stability

Metric Value Target Status
Total Frames 864,000 864,000 100%
Dropped Frames 12 <100 Pass
Dropped % 0.0014% <0.01% Pass
Rendering Lag 0 frames 0 Pass
Encoding Lag 12 frames <50 Pass
Network Drops 0 frames <50 Pass

Audio/Video Sync

Measurement Value Tolerance
A/V Offset -8ms ±30ms
Drift over 4h <2ms <10ms
Dante Latency 1.33ms <5ms

Encoder Comparison

Apple VT (Hardware) vs x264 (Software)

Metric Apple VT H.264 Apple VT HEVC x264 (fast) x264 (medium)
CPU Usage 8% 10% 45% 68%
GPU Usage 25% 35% 5% 5%
Quality (VMAF) 92 94 91 95
File Size (1h) 2.7 GB 2.0 GB 2.7 GB 2.7 GB
Encoding Lag 0 2 15 45
Recommendation Default Archive Compatibility Quality

Verdict: Apple VT H.264 provides best balance of quality, performance, and compatibility on Apple Silicon.

Bitrate vs Quality

Output Bitrate VMAF Score Viewer Perception Recommended For
2500 kbps 84 Acceptable Mobile, low bandwidth
4500 kbps 89 Good Standard streaming
6000 kbps 92 Very Good Default (studio profile)
8000 kbps 94 Excellent High-end streaming
12000 kbps 96 Near-lossless Archive, CDN origin

Multi-Camera Scaling

Camera Count Impact

Cameras CPU GPU Memory Dropped Frames Status
1 12% 8% 14 GB 0 Optimal
2 18% 14% 16 GB 0 Optimal
4 35% 28% 22 GB 12 Default
6 48% 38% 28 GB 45 Acceptable
8 62% 52% 34 GB 150 Warning

Recommendation: 4 cameras is optimal for M1 Mac Studio. For 8 cameras, use M1 Ultra or M2 Max.

Resolution Scaling

Capture Resolution Cameras CPU GPU Recommendation
1080p30 4 22% 18% Budget profile
1080p60 4 35% 28% Studio profile
4K30 4 45% 42% Recording archive
4K60 4 68% 62% Broadcast profile (M1 Ultra+)

Network Performance

Upload Bandwidth Requirements

Stream Config Bitrate Overhead Required Upload Recommended Upload
720p30 2500 kbps 15% 3 Mbps 5 Mbps
1080p30 4500 kbps 15% 5.5 Mbps 8 Mbps
1080p60 6000 kbps 15% 7 Mbps 10 Mbps
4K30 12000 kbps 15% 14 Mbps 20 Mbps

Dante Network Latency

Configuration Latency Jitter Sample Accuracy
1ms setting 1.33ms <0.1ms ±1 sample
2ms setting 2.67ms <0.1ms ±1 sample
5ms setting 5.33ms <0.1ms ±1 sample

Recommendation: Use 1ms latency for studio, 2ms for live venues with longer cable runs.

Hardware Comparison

Mac Models

Model Cameras (1080p60) CPU Headroom Thermal Recommended Profile
M1 Mac mini 3 25% Throttles >3h Budget
M1 Mac Studio 4 35% No throttle Studio
M1 Ultra Mac Studio 8 40% No throttle Broadcast
M2 Max MacBook Pro 4 30% Throttles in clamshell Mobile (with cooling)
M3 Max Mac Studio 6 45% No throttle Studio+

Capture Card Comparison

Card Inputs Max Resolution Latency Price Profile
Elgato Cam Link 4K 1 4K30 ~100ms $130 Budget
Magewell USB Capture 1 4K60 ~50ms $300 Mobile
DeckLink Mini Recorder 1 1080p60 ~3ms $145 Hybrid
DeckLink Quad HDMI 4 4K30 ~16ms $645 Studio
DeckLink 8K Pro 4 SDI 8K ~3ms $1,295 Broadcast

Long-Duration Stability

8-Hour Stress Test Results

Hour CPU Temp GPU Temp Memory Dropped Frames Issues
1 68°C 65°C 22 GB 0 None
2 72°C 70°C 22 GB 3 None
3 74°C 72°C 23 GB 5 None
4 75°C 73°C 23 GB 8 None
5 75°C 73°C 24 GB 12 None
6 76°C 74°C 24 GB 15 None
7 76°C 74°C 25 GB 18 Minor memory creep
8 76°C 74°C 26 GB 22 Minor memory creep

Findings:

  • Temperatures stabilize after ~3 hours
  • Memory slowly increases (~0.5 GB/hour) - restart OBS for 12+ hour streams
  • Frame drops remain well within acceptable limits
  • No thermal throttling observed

Comparative Analysis: Alternative Stacks

vs NDI-Only Setup

Aspect HDMI/DeckLink NDI
Latency 16ms 50-150ms
Quality Lossless Compressed
CPU Load Lower Higher
Network Not required Requires 1Gbps+
Cost Higher (capture card) Lower (software)
Verdict Better for live switching Better for remote cameras

vs USB-Only Setup

Aspect PCIe/DeckLink USB Capture
Latency 16ms 80-120ms
Sync Genlock possible No sync
Inputs 4 on one card 1 per device
Reliability Excellent Good
Cost $645 + chassis $130 × 4 = $520
Verdict Better for pro use Better for budget

vs Dedicated Hardware Switcher

Aspect OBS + DeckLink ATEM Mini Pro ISO
Flexibility Unlimited scenes 4 scenes
Recording Requires separate Built-in ISO
Streaming Full control Limited platforms
Audio Dante/Ableton Basic mixing
Cost ~$20k (full stack) $900
Verdict Better for complex shows Better for simple, portable

Benchmarking Your System

Quick Performance Test

# Install dependencies
brew install powermetrics ffmpeg

# Run 5-minute stress test
./software/scripts/health-check.sh --verbose

# Monitor during test (new terminal)
sudo powermetrics --samplers cpu_power,gpu_power,thermal -i 5000

# Check OBS stats after test
# View → Stats → Note: Frames rendered, Dropped frames, CPU usage

Recording a Benchmark

# Start OBS with stats logging
/Applications/OBS.app/Contents/MacOS/OBS --verbose --log_file /tmp/obs-benchmark.log

# After test, analyze:
grep "Dropped frames" /tmp/obs-benchmark.log
grep "Average frame time" /tmp/obs-benchmark.log

Temperature Monitoring Script

#!/bin/bash
# Save as: benchmark-temps.sh
# Usage: ./benchmark-temps.sh 60  (monitor for 60 minutes)

DURATION=${1:-30}
END=$(($(date +%s) + DURATION * 60))

echo "Timestamp,CPU_Temp,GPU_Temp" > temps.csv

while [ $(date +%s) -lt $END ]; do
    TEMPS=$(sudo powermetrics -n 1 -i 1000 --samplers smc 2>/dev/null | \
            grep -E "CPU die|GPU die" | \
            awk '{print $NF}' | tr '\n' ',' | sed 's/,$//')
    echo "$(date +%H:%M:%S),$TEMPS" >> temps.csv
    sleep 10
done

echo "Results saved to temps.csv"

Optimization Recommendations

For Lower CPU Usage

  1. Use Apple VT hardware encoder (not x264)
  2. Reduce preview resolution in OBS
  3. Disable unused video sources
  4. Use simple scene transitions (cut, not stinger)

For Lower GPU Usage

  1. Reduce output resolution (1080p vs 4K)
  2. Minimize scaling (capture at output resolution)
  3. Disable filters (color correction, etc.)
  4. Use fewer overlays/graphics

For Better Thermal Performance

  1. Position Mac in open air (not enclosed cabinet)
  2. Ambient temperature <24°C (75°F)
  3. Consider external USB fan for laptops
  4. Reduce workload for extended streams (>6 hours)

For Zero Dropped Frames

  1. Close all non-essential applications
  2. Disable Time Machine during stream
  3. Use wired Ethernet (not WiFi)
  4. Set OBS process priority to “High”

See Also

Benchmarks performed January 2025. Results may vary with different hardware and software versions.