2.4.3. Neutron v6 Architecture#

Neutron v6 vNPU

Neutron v6 iteratively optimizes the power consumption and area of the Neutron v4 architecture. It retains an overall organization of 1 NPU Core, 1 CONV, 1 TENG, 1 SDMA, and optional dual-vNPU time-division multiplexing.

  • Like Neutron v4, Neutron v6 divides EUs into compute and data-movement types. With time-division multiplexing enabled, two logical vNPUs can overlap the computation and communication stages of different inference tasks. The two logical vNPUs share on-chip resources, so each vNPU has less OCM available than the complete NPU resource with multiplexing disabled.

  • Some Neutron v6 platforms expose only the single-NPU resource mode. See the runtime modes and npu_mode descriptions below for the available options.

2.4.3.1. Runtime modes and npu_mode#

2.4.3.1.1. AXEngine runtime modes#

Chip platform

AXEngine runtime mode

Compute resources

AX615

AX_ENGINE_VIRTUAL_NPU_ENABLE

Enables logical vNPU partitioning and schedules two vNPUs on the same NPU Core through hardware time-division multiplexing. The two logical vNPUs share on-chip resources, reducing the OCM available to each vNPU.

AX615

AX_ENGINE_VIRTUAL_NPU_DISABLE

Disables logical vNPU partitioning and hardware time-division multiplexing. One complete NPU resource is exposed at runtime, and the model uses all NPU resources for inference.

M57

AX_ENGINE_VIRTUAL_NPU_DISABLE

Only the single-NPU resource mode is supported.

AX637

AX_ENGINE_VIRTUAL_NPU_DISABLE

Only the single-NPU resource mode is supported.

2.4.3.1.2. Offline npu_mode and hardware resources#

Chip platform

npu_mode

Hardware compute resources

AX615

NPU1

Compilation resources for one logical vNPU in time-division multiplexing mode, with less OCM available than in complete NPU resource mode.

AX615

NPU2

Complete NPU compilation resources with time-division multiplexing disabled. All NPU resources are used for inference, with more OCM available than to one logical vNPU in multiplexing mode.

M57

NPU1

One NPU Core containing 1 CONV, 1 TENG, 1 DAU, and 1 SDMA.

AX637

NPU1

One NPU Core containing 1 CONV, 1 TENG, 1 DAU, and 1 SDMA.