"""On-silicon memory measurement. Nothing here is modelled. python scripts/py/silicon_mem.py Every figure is read from the card: cluster `busy_cycles` from `CU_COUNTERS`, and error percentiles against a float64 reference. The bandwidth is the SLOPE of busy cycles against operand bytes across shapes, not a single point -- a single point carries the fixed dispatch cost and reads low. """ import kohakutpu.units # noqa: F401 (registers MG and VC) import numpy as np from kohakuaccel.device import control_read from kohakuaccel.device.registers import CU_COUNTERS from kohakuaccel.transport.jtag import JtagTransport from kohakutpu.host import Card from kohakutpu.meshes import MeshGroup from kohakutpu.ops import matmul BOARD = "multimesh_v7" def busy(mesh) -> int: """Total busy cycles over every cluster on this mesh.""" total = 0 for coord in mesh.coords("MG"): word = control_read(mesh.ctrl, coord, CU_COUNTERS) if word is not None: total += word & 0xFFFF_FFFF return total def main() -> int: t = JtagTransport() card = Card.from_board(BOARD, transport=t, which=[0]) mesh = card.mesh head = MeshGroup.open(card, [0])[0] rng = np.random.default_rng(11) print(f"{mesh}") print("ON SILICON -- mesh 0, clocks as programmed. No model anywhere.\n") print( f"{'M':>4}{'K':>6}{'N':>5} {'operand B':>10} {'busy cyc':>10} " f"{'B/cyc':>8} {'p50 rel':>10} {'p99 rel':>10}" ) rows = [] for k in (128, 256, 512): m, n = 64, 128 a = rng.normal(0, 0.02, (m, k)).astype(np.float16) b = rng.normal(0, 1.00, (n, k)).astype(np.float16) want = a.astype(np.float32) @ b.astype(np.float32).T before = busy(mesh) got = matmul(head.tensor(a), head.tensor(b), gm=8, gn=8, nk=2).numpy() cycles = (busy(mesh) - before) % (1 << 32) nbytes = (m * k + n * k) * 2 scale = np.maximum(np.abs(want), np.abs(want).max() * 1e-3) rel = np.abs(got - want) / scale rows.append((nbytes, cycles)) print( f"{m:>4}{k:>6}{n:>5} {nbytes:>10,} {cycles:>10,} " f"{nbytes / max(cycles, 1):>8.2f} " f"{np.percentile(rel, 50):>10.3e} {np.percentile(rel, 99):>10.3e}" ) if len(rows) > 1: d_bytes = rows[-1][0] - rows[0][0] d_cycles = rows[-1][1] - rows[0][1] per = d_bytes / max(d_cycles, 1) print(f"\nslope: +{d_bytes:,} B / +{d_cycles:,} cyc = {per:.2f} B/cycle") print( f" = {per * 100e6 / 1e9:.2f} GB/s at a 100 MHz clock, " f"{per * 300e6 / 1e9:.2f} at 300 MHz" ) return 0 if __name__ == "__main__": raise SystemExit(main())