Commit Graph
2 Commits
Author SHA1 Message Date
micheleandClaude Sonnet 5 cbd16dd727 docs: sync physical/architecture docs with EXP-0081/0082 reality, add 32-bit vs dual-channel analysis
- PHYSICAL_REALIZATION.md: replace stale "1 tile = 1 burst" layout
  description with the real EXP-0081/0082 "2 tiles = 1 burst" convention;
  add EXP-0082 signoff row and history table.
- ARCHITECTURE_ANALYSIS.md: mark §5.1 (denser activation packing) DONE with
  real re-measured numbers (bandwidth ceiling fraction 25%->50%, WNS
  +0.030->+0.068ns); add §5.4, the real device-data-backed comparison of
  32-bit single-channel widening vs a second independent DDR3 channel
  (decided: 32-bit widening, per real DQS/bank pin-conflict analysis);
  update scaling-path recommendation to reflect the user's final directive
  (widen channel -> build DDRManager -> N=2/4/8/16 tests, N=8 target, N=16
  documentary).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MUG92aM9m68TRc4rG55BcC
2026-09-20 10:07:16 +02:00
micheleandClaude Sonnet 5 27cf5f36da docs: complete architecture analysis - DDR3 bandwidth is the real ceiling, not DSP count (EXP-0080)
Before building N=4/8/16 core scaling, did the requested full
analysis. Real finding: using measured DDR3 throughput (1.24 GB/s,
from the actual EXP-0079 JEDEC trace) against calculated compute-side
need (4.96 GB/s for one core at peak DSP throughput, given the
current activation memory layout's 2x byte overhead), the system is
memory-bandwidth-bound already at N=1/N=2, not DSP-bound (only 6.67%
DSP used). Scaling core count today would show no real throughput
gain.

docs/ARCHITECTURE_ANALYSIS.md: full module review + ranked
interventions -- result-writeback engine (blocker), denser activation
packing (highest-leverage bandwidth fix), then the user's own proposed
DDRManager/orchestrator-prefetch idea (design-sketched, grounded in
neural_director_packed.v's existing job queue, explicitly scoped as
complementary to denser packing, not a substitute for it), THEN
N-scaling with real per-N P&R signoff.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MUG92aM9m68TRc4rG55BcC
2026-09-20 09:44:10 +02:00