BLIIoT’s ARMxy series embedded ARM industrial computers adopt both ARM Cortex-A55 and Cortex-A72 processors. To help users quickly select the right ARM processor, the following comparison table highlights the differences between Cortex-A55 and Cortex-A72. Within the ARMxy product line, the BL410 uses the industrial-grade RK3568J quad-core Cortex-A55, while the BL440 features the industrial-grade RK3576J quad-core A72 + quad-core A53 processor.
| Dimension | Cortex-A55 (2017) | Cortex-A72 (2015) |
|---|---|---|
| Design Focus | Power efficiency (little core) | Performance priority (big core) |
| Market Position | Mid/low-end devices, co-processor | Flagship devices, main CPU core |
| Typical Config. | 4–8 core clusters | 1–4 high-performance cores |
Key differences:
Decode width: A72 has 4 decode ports vs 3 in A55
Pipeline depth: A72 is deeper (15 vs 10 stages), enabling higher frequencies
Execution resources: A72 integrates more ALU/FPU units
| Test Item | A55 @ 2.0GHz | A72 @ 2.5GHz | Gap |
|---|---|---|---|
| SPECint2006 | 6.5 | 11.8 | +81% |
| FP32 Perf. | 28 GFLOPS | 60 GFLOPS | +114% |
| Memory Latency | 24 cycles | 18 cycles | -25% |
📌 Note: At the same frequency (2.0GHz), the A72 still delivers ~40% higher single-thread performance.
| Parameter | A55 (16nm) | A72 (16nm) |
|---|---|---|
| Typical Power | 0.8W | 2.5W |
| Efficiency (DMIPS/mW) | 3.4 | 1.9 |
| Idle Power | 30mW | 80mW |
👉 Efficiency edge: At the same process node, A55 delivers ~80% higher performance-per-watt.
A55 unique features:
ARMv8.2 ISA (FP16 / INT8 support)
Memory Tagging Extension (MTE)
Accelerator Coherency Port
A72 advantages:
Larger L2 cache (1MB vs 256KB)
AMBA4 ACE bus (higher bandwidth)
| Field | A55 Suitable Use Case | A72 Suitable Use Case |
|---|---|---|
| Smartphones | Efficiency cores (co-CPU) | Performance cores (main CPU) |
| Industrial Control | Sensor aggregation node | Machine vision processing |
| Automotive | Infotainment system | ADAS pre-processing |
| Edge Computing | Lightweight AI inference | Complex algorithm workloads |
Cortex-A55 based:
Rockchip RK3568 (4×A55 + NPU)
Qualcomm Snapdragon 6 Gen1 (4×A55)
Cortex-A72 based:
Rockchip RK3576 (4×A72 + 4×A53)
HiSilicon Kirin 950 (4×A72)
Choose A55 when:
✓ Power efficiency is critical (battery-powered devices)
✓ Running lightweight AI workloads (INT8 quantized models)
✓ Cost-sensitive projects (BOM cost ~30% lower)
Choose A72 when:
✓ Desktop-class CPU performance is required
✓ Running high-complexity algorithms (e.g., SLAM)
✓ System requires large cache support (≥1MB L2)
A55: Still the mainstream efficiency core, paired with A78/A710 in modern heterogeneous designs
A72: Gradually replaced by A76/A78 in consumer devices, but still widely deployed in industrial solutions
📌 Technology evolution: Modern DynamIQ heterogeneous architectures usually combine A55 efficiency cores with A7x performance cores, achieving optimal performance-per-watt balance.
