Allreduce + pe2pe + ipcq + pe_view auto-regenerated by test sweeps
running against the new chunk-streaming wire timing (per-flit
wormhole) — absolute numbers shift upward to reflect bottleneck-link
transit charged once per flit (instead of the previous cut-through
subtraction at HBM CTRL).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Move the algorithmic root cube from the corner (cube_w-1,
cube_h-1) to the geometric center (cube_w//2, cube_h//2) and
have each phase converge bidirectionally so the intra-SIP
critical path drops from ~12 hops to ~8 hops on a 4×4 mesh
(left half W→E + right half E→W in row reduce; top half N→S +
bottom half S→N in col reduce; mirrored on broadcast).
Result on torus_2d 6 SIPs at 96 KB / PE on TCM:
before (corner root) : 22.0 µs
after (center root) : 17.2 µs (−22%)
Same shape on ring_1d (−7%) and mesh_2d_no_wrap (−12%); also
holds across SRAM and HBM (~−20% each).
Phase 1 test (test_intercube_root_center.py) asserts the
torus_2d 96 KB latency drops below 20.5 µs and that all 96
cubes still validate (correctness preserved).
Plot updates:
- overview.png: replace constant 10.6 µs theoretical line with
user-supplied hand-derived curve (per-cube packet count =
bytes_per_pe × 8 PEs ÷ 128 B; 1346 ns startup + 1.20 ns/pkt).
- All summary.csv numbers and per-topology PNGs regenerated.
- pe2pe_latency_plots and ipcq diagram emitter PNGs refreshed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
ywkang
mukesh