Model whether the on-chip network keeps up with the cores it connects — then run it: the simulation
executes on the ChipFoundryServices distributed compute pool. Cores, caches and memory controllers talk over a
packet-switched fabric, usually a k×k mesh or torus of routers. A packet crossing
H hops pays, per hop, a router pipeline plus a link traversal; its tail then serializes one flit per
cycle — zero-load latency T₀ = H·(t_r + t_w) + L. As offered load rises,
contention adds queueing delay ≈ T₀/(1 − ρ), the classic latency hockey
stick that shoots up near saturation. Throughput under uniform traffic is bottlenecked at the network
bisection: a mesh cuts into 2k channels, so the per-node saturation injection rate falls like
~1/k — bigger fabrics saturate at lower per-node bandwidth. A torus wraps around,
doubling the bisection (and roughly the throughput) at the cost of longer links, while virtual channels and
buffering recover a fraction of the ideal limit that head-of-line blocking would waste. Reduced-order educational
model. See also the clock-tree, place-and-route,
power-delivery network, electromigration,
interconnect RC, SerDes link,
chiplet / CoWoS, HBM bandwidth and
systolic array simulators and the compute-pool status.
~1/k, so larger fabrics saturate lower (marker ● = your k). Right: the latency budget — zero-load and average latency as a share of the budget, and offered load as a share of saturation (100 % = at the edge)curl -X POST https://www.chipfoundryservices.com/edge/noc \
-H "Content-Type: application/json" \
-d '{"mesh_radix_k":8,"torus_enable":0,"injection_rate":0.15,"packet_size_flits":5,
"link_width_bits":128,"router_freq_mhz":1500,"router_stages":3,"link_cycles":1,
"virtual_channels":4,"buffer_depth_flits":8,"latency_budget_ns":100}'
Returns JSON with outputs (num_nodes, avg_hops, diameter_hops, zero_load_latency_ns, avg_latency_ns,
serialization_latency_ns, hop_latency_ns, queueing_latency_ns, load_percent, saturation_injection_rate,
accepted_injection_rate, routing_efficiency_percent, flit_bytes, link_bandwidth_gbps, bisection_channels,
bisection_bandwidth_gbps, injected_bw_per_node_gbps, aggregate_throughput_gbps, meets_budget,
latency_headroom_percent, dominant_component, topology, verdict), the full profile (48-point
latency_vs_load sweep [injection_rate, avg_latency_ns] and 48-point
sat_vs_radix sweep [mesh_radix_k, saturation_injection_rate]), the serving
node, and compute_ms. Endpoint aliases /edge/networkonchip,
/edge/interconnectfabric, /edge/meshnetwork, /edge/torus,
/edge/routerlatency, /edge/bisection.