RDMA로 맥 풀링하기: 종이 위와 실제

#!/usr/bin/env python3
"""Pooling Macs over RDMA: on paper and in practice. Apple's requirement, the fleet's
qualification against it, and two public multi-Mac results run through the physics track.
No RDMA run in this quest; the household's own verdict is labelled judgment."""
FLEET = [  # alias, chip, Thunderbolt generation (Apple spec pages), memory GB
    ("office", "M3 Ultra", 5, 512), ("server", "M3 Ultra", 5, 512), ("macbook", "M5 Max", 5, 128), ("pro2024", "M4 Max", 5, 128),
    ("mini", "M4 Pro", 5, 64), ("worker", "M2 Ultra", 4, 192), ("music", "M2 Ultra", 4, 192), ("pro2023", "M3 Max", 4, 128), ("air", "M3", 4, 24),
]
print("Apple TN3205: 'RDMA over Thunderbolt is available starting with macOS 26.2 on Macs with Apple silicon with Thunderbolt 5.'")
q = [f for f in FLEET if f[2] == 5]
print(f"qualifies: {[f[0] for f in q]}  pooled memory {sum(f[3] for f in q)} GB;  does not: {[f[0] for f in FLEET if f[2] < 5]}")
print("the two 512 GB Studios are the only pair worth pooling: 1,024 GB behind one 10 GB/s cable, versus 2.5 TB/s inside each\n")

# public results, read for this quest; 't/s' as charted, stage unlabelled in the source
BW = 819
public = [  # who, setup, model, bytes/token active (DERIVED), t/s by Mac count
    ("Geerling 2025-12-18, exo RDMA", "4x M3 Ultra (2x512, 2x256 GB)", "Qwen3 235B-A22B 8-bit", 22 * 1.06, {1: 19.5, 2: 26.2, 4: 31.9}),
    ("Geerling 2025-12-18, exo RDMA", "same",                          "DeepSeek V3.1 671B-A37B 8-bit", 37 * 1.06, {1: 21.1, 2: 27.8, 4: 32.5}),
    ("MLX discussion #2990, 2026-01",  "5x M3 Ultra 512 GB",            "Kimi-K2-Thinking Q4 (32B active)", 32 * 0.6, {4: 14.49, 5: 14.45}),
]
for who, setup, model, bpt, rates in public:
    ceiling = BW / bpt
    print(f"{who}: {model} on {setup}")
    for n, r in rates.items():
        flag = "  <- above one Mac's ceiling at the stated bits: wrong bits, wrong stage, or more than one token per pass" if r > ceiling and n == 1 else ""
        print(f"    {n} Mac(s): {r:5.1f} t/s  = {r/ceiling*100:3.0f}% of one Mac's ceiling ({ceiling:.0f}); vs fewest Macs x{r/rates[min(rates)]:.2f}{flag}")
print("\nreadings: adding Macs buys 1.3-1.6x at 2 and 1.5-1.6x at 4 in the exo runs; the 5-Mac pipeline is within 0.3% of the 4-Mac one, and tensor-parallel on 4 within 2.3% of pipeline on 4.")
print("exo's own README claims 'up to 1.8x speedup on 2 devices and 3.2x speedup on 4 devices' -- a ceiling the charts did not reach.")