VERIFIED MULTICHANNEL AES67
64 channels at 1 ms.
256 at 3 ms.
Measured on the same quad-core Arm Cortex-A72 reference platform and verified through the final ALSA PCM boundary.
BAMA BOX VERIFIED SCALINGSAME ARM PLATFORM
channels
16 streams × 8 channelschannels
32 streams × 8 channelsConfigured receiver targets · verified logical ALSA output channels
EXECUTIVE BENCHMARK SUMMARY
Capacity rises with the configured receiver target.
Reference platform: Raspberry Pi 4, quad-core Arm Cortex-A72, Debian 12, direct physical 1 Gb Ethernet and software PTP/software timestamps. Final performance is established on the OEM target SoC.
| Channels | Measured topology | Packet time | Receiver target | Receiver CPU | System CPU | RSS | Validation boundary |
|---|---|---|---|---|---|---|---|
| 64 | 8 streams × 8 channels | 0.5 ms | 1 ms | 0.5200 cores | See report note | 90.7 MiB | Packet · clock · presentation · final ALSA PCM |
| 128 | 16 streams × 8 channels | 1 ms | 2 ms | 0.7926 cores | 1.3868 cores | 98.9 MiB | Packet · clock · presentation · final ALSA PCM |
| 256 | 32 streams × 8 channels | 1 ms | 3 ms | 2.2317 cores | 2.3415 cores | 115.5 MiB | Packet · clock · presentation · final ALSA PCM |
The 64-channel receiver CPU is the report's comparable getrusage value; its whole-system CPU window was not aligned for a direct table comparison. These are verified logical ALSA output channels, not physical outputs or product ceilings.
MATCHED 64-CHANNEL WORKLOADSame 8 × 8-channel workload.
Same 8 × 8-channel workload.
Different first passing targets.
The unchanged stock RAVENNA/Linux path and Bama Box were exercised through the common daemon configuration at 64 channels.
strict presentation gate passed
Packet, clock, presentation and final ALSA PCM gates passed for the 64-channel workload.
first final ALSA capture pass
Final ALSA capture continuity failed at 1 and 2 ms and passed at the configured 3 ms target.
channels exposed by tested configurations
Bama Box sustained 256 logical channels; the tested common RAVENNA configuration exposed 64 usable input routes.
Scope: the four-times figure compares usable channel counts exposed by the tested configurations. The 64-route result was a control/configuration limit—not a measured RAVENNA CPU ceiling or a limit of the RAVENNA standard. The validation boundaries differ.
REAL HARDWARE OUTPUT
1 ms configured receiver target sustained through PCM5122/I²S.
One stereo RTP/L16 stream sustained through ALSA → I²S → PCM5122 with a maximum runtime ALSA queue of 34 frames / 0.71 ms.
SENDERmacOSRTP/L16 + PTPd2 GM
→NETWORKDirect 1 GbEno intervening switch
→RECEIVERBCM27114× Cortex-A72
→OUTPUTPCM5122 / I²S34 frames / 0.71 ms max queue
This validates the configured receiver target through the physical PCM device path. It is not an analog or network-to-DAC end-to-end latency measurement.
X86 BACKSTAGE POTENTIAL
Receiver efficiency beyond embedded endpoints.
A separate cloud KVM/Linux-container benchmark exercised a 32-channel workload through the UDP fallback available in that environment. It shows potential for mixers, console engines and backstage servers; direct packet access depends on the OEM security configuration.
6×lower CPU load
11×lower memory
32 audio channels · compared with FFmpeg on the same x86/KVM environment
METHODOLOGY + SCOPE
What the results establish.
The measurements remain separated so channel scale, physical output and x86 resource evidence are not presented as one implied apples-to-apples matrix.
Multichannel boundary
Logical ALSA output validation across the shared receive and decode path. It does not represent a 256-channel physical PCM device.
Clock environment
Software PTP and software timestamps on the Arm reference platform; no PHC or hardware timestamps.
256-channel nuance
The 3 ms run passed all gates. Maximum recorded per-stream packet-service gap was 6.395 ms; 256 channels at 2 ms were not qualified.
Comparison boundary
RAVENNA validates final ALSA capture continuity; Bama Box adds exact RTP-to-presentation instrumentation.
MEASURE YOUR PRODUCT TARGET
Plan a joint benchmark Move from reference data to your hardware.
We can reproduce the receiver benchmark using your SoC, timing source, NIC and audio interface.