Run the test_intranode.py test file, the bandwidth result is very large.

Using two H100 GPUs (the machine has an 8-GPU setup), we tested test_intranode.py and increased the SM count（100）.

The test bandwidth hit 500 GB/s, which exceeds the theoretical limit.

[tuning] SMs 100, NVL chunk 4: 357.23 GB/s (NVL), avg_t: 168.89 us
[tuning] SMs 100, NVL chunk 6: 403.38 GB/s (NVL), avg_t: 149.57 us
[tuning] SMs 100, NVL chunk 8: 431.41 GB/s (NVL), avg_t: 139.85 us
[tuning] SMs 100, NVL chunk 10: 440.36 GB/s (NVL), avg_t: 137.01 us
[tuning] SMs 100, NVL chunk 12: 461.04 GB/s (NVL), avg_t: 130.86 us
[tuning] SMs 100, NVL chunk 14: 447.61 GB/s (NVL), avg_t: 134.79 us
[tuning] SMs 100, NVL chunk 16: 433.24 GB/s (NVL), avg_t: 139.26 us
[tuning] SMs 100, NVL chunk 18: 442.79 GB/s (NVL), avg_t: 136.26 us
[tuning] SMs 100, NVL chunk 20: 432.81 GB/s (NVL), avg_t: 139.40 us
[tuning] SMs 100, NVL chunk 22: 431.02 GB/s (NVL), avg_t: 139.98 us
[tuning] SMs 100, NVL chunk 24: 430.64 GB/s (NVL), avg_t: 140.10 us
[tuning] SMs 100, NVL chunk 26: 410.76 GB/s (NVL), avg_t: 146.88 us
[tuning] SMs 100, NVL chunk 28: 411.30 GB/s (NVL), avg_t: 146.69 us
[tuning] SMs 100, NVL chunk 30: 411.45 GB/s (NVL), avg_t: 146.64 us
[tuning] SMs 100, NVL chunk 32: 407.09 GB/s (NVL), avg_t: 148.21 us
[tuning] SMs 100, NVL chunk default: 426.58 GB/s (NVL), avg_t: 141.44 us
[tuning] Best dispatch (FP8): SMs 100, NVL chunk 12, 461.04 GB/s (NVL), t: 130.86 us

[tuning] SMs 100, NVL chunk 4: 502.98 GB/s (NVL), avg_t: 232.63 us
[tuning] SMs 100, NVL chunk 6: 527.64 GB/s (NVL), avg_t: 221.76 us
[tuning] SMs 100, NVL chunk 8: 514.80 GB/s (NVL), avg_t: 227.29 us
[tuning] SMs 100, NVL chunk 10: 515.64 GB/s (NVL), avg_t: 226.92 us
[tuning] SMs 100, NVL chunk 12: 501.99 GB/s (NVL), avg_t: 233.09 us
[tuning] SMs 100, NVL chunk 14: 489.89 GB/s (NVL), avg_t: 238.85 us
[tuning] SMs 100, NVL chunk 16: 494.01 GB/s (NVL), avg_t: 236.86 us
[tuning] SMs 100, NVL chunk 18: 482.13 GB/s (NVL), avg_t: 242.70 us
[tuning] SMs 100, NVL chunk 20: 481.67 GB/s (NVL), avg_t: 242.93 us
[tuning] SMs 100, NVL chunk 22: 471.47 GB/s (NVL), avg_t: 248.18 us
[tuning] SMs 100, NVL chunk 24: 466.69 GB/s (NVL), avg_t: 250.73 us
[tuning] SMs 100, NVL chunk 26: 456.21 GB/s (NVL), avg_t: 256.48 us
[tuning] SMs 100, NVL chunk 28: 452.76 GB/s (NVL), avg_t: 258.44 us
[tuning] SMs 100, NVL chunk 30: 448.46 GB/s (NVL), avg_t: 260.92 us
[tuning] SMs 100, NVL chunk 32: 440.58 GB/s (NVL), avg_t: 265.58 us
[tuning] SMs 100, NVL chunk default: 466.06 GB/s (NVL), avg_t: 251.06 us
[tuning] Best dispatch (BF16): SMs 100, NVL chunk 6, 527.64 GB/s (NVL), t: 221.76 us

[tuning] SMs 100, NVL chunk 1: 174.69 GB/s (NVL), avg_t: 669.82 us
[tuning] SMs 100, NVL chunk 2: 309.17 GB/s (NVL), avg_t: 378.47 us
[tuning] SMs 100, NVL chunk 3: 395.33 GB/s (NVL), avg_t: 295.98 us
[tuning] SMs 100, NVL chunk 4: 445.00 GB/s (NVL), avg_t: 262.95 us
[tuning] SMs 100, NVL chunk 5: 468.89 GB/s (NVL), avg_t: 249.55 us
[tuning] SMs 100, NVL chunk 6: 491.77 GB/s (NVL), avg_t: 237.94 us
[tuning] SMs 100, NVL chunk 7: 503.19 GB/s (NVL), avg_t: 232.54 us
[tuning] SMs 100, NVL chunk 8: 495.00 GB/s (NVL), avg_t: 236.38 us
[tuning] SMs 100, NVL chunk 9: 490.27 GB/s (NVL), avg_t: 238.66 us
[tuning] SMs 100, NVL chunk 10: 489.83 GB/s (NVL), avg_t: 238.88 us
[tuning] SMs 100, NVL chunk 11: 483.32 GB/s (NVL), avg_t: 242.10 us
[tuning] SMs 100, NVL chunk 12: 484.54 GB/s (NVL), avg_t: 241.49 us
[tuning] SMs 100, NVL chunk 13: 480.66 GB/s (NVL), avg_t: 243.44 us
[tuning] SMs 100, NVL chunk 14: 470.20 GB/s (NVL), avg_t: 248.85 us
[tuning] SMs 100, NVL chunk 15: 475.32 GB/s (NVL), avg_t: 246.17 us
[tuning] SMs 100, NVL chunk 16: 466.02 GB/s (NVL), avg_t: 251.08 us
[tuning] SMs 100, NVL chunk default: 488.77 GB/s (NVL), avg_t: 239.40 us
[tuning] Best combine: SMs 100, NVL chunk 7: 503.19 GB/s (NVL), t: 232.54 us

What is the reason for this?