The hardware and system substrate supplies compute, memory, storage, networking, isolation, drivers, and topology information to every runtime layer above it.
Responsibilities
- Expose CPU, GPU, TPU, NPU, FPGA, and accelerator capabilities.
- Provide memory hierarchy, DMA, IOMMU, NUMA, storage, and interconnect behavior.
- Enforce process, container, virtual-machine, and tenant isolation.
- Surface thermal, power, availability, and failure signals.
Boundary
This layer does not decide model quality, request policy, or business workflow. It defines the physical and operating constraints within which kernels and runtimes execute.