98 lines
3.8 KiB
Python
98 lines
3.8 KiB
Python
"""Ascend950PR (DAV_3510) 硬件规格参数.
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数值来源: 《BMM算子优化分析 v0.98》§二 + 昇腾950 NPU架构白皮书.
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换芯片时逻辑结构不变, 只需新增一份同结构参数表.
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单位约定: 算力 FLOP/s, 带宽 Byte/s, 容量 Byte, 时延 秒.
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"""
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from __future__ import annotations
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from dataclasses import dataclass
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@dataclass(frozen=True)
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class NpuSpec:
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name: str = "Ascend950PR"
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# ---- 核数与算力 ----
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aic_num: int = 32 # C: AIC (Cube) 核数
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aiv_num: int = 64 # AIV (Vector) 核数
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cube_peak_tflops: float = 486.0 # 全芯片 Cube BF16 标称算力 (乘加各计一次)
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aiv_freq_ghz: float = 1.65
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aiv_fp32_per_cycle: int = 128 # 单 AIV 每拍 fp32 求和吞吐
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# ---- 片上存储 (每核) ----
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l1_bytes: int = 512 * 1024 # L1 Buffer 512KB
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l0a_bytes: int = 64 * 1024 # L0A 64KB
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l0b_bytes: int = 64 * 1024 # L0B 64KB
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l0c_bytes: int = 256 * 1024 # L0C 256KB (fp32 累加, 4B/元素)
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# ---- L2 / GM ----
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l2_bytes: int = 128 * 1024 * 1024 # L2 Cache 128MB
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bw_l2: float = 5.2e12 # L2 读写带宽 5.2TB/s
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bw_gm: float = 1.6e12 # GM(HBM) 带宽 1.6TB/s (读写共享)
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# ---- 搬移效率经验约束 (950PR 实测总结) ----
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dvalue_recommend: int = 512 # dValue 推荐值 (Byte), 更大无额外收益
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dvalue_min: int = 128 # dValue 下限 (Byte)
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dvalue_hw_min: int = 256 # DMA 硬件突发下限 (Byte) —— 尾轮文档 §2.3
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min_tile_size: int = 16 * 1024 # min_TileSize: 单块搬移最小量 16KB
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min_datamount_per_core: int = 480 * 1024 # min_DatamountPerCore: 单核搬移总量下限 480KB
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min_core_num_ratio: float = 0.8 # minCoreNum ≈ 0.8 * C (经验: 约 3/4 核并发才达 90%+ 带宽利用率)
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# ---- DMA 固定开销 ----
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t_cmd_ns: float = 50.0 # T_cmd: 单次 GM->L1 DMA 命令固定开销 (ns, 估计值, 需实测标定)
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# ---- 带宽模型假设 (issue#26) ----
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# GM 1.6TB/s 为读写共享总线 (读+写累加计时); L2 带宽读写各自独享 5.2TB/s;
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# active_cores < C 时按"每核份额线性配平"为模型假设 (如 1 核也给 50GB/s),
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# 真实低核数带宽利用率低于线性, 需 msProf 实测曲线标定后替换该假设.
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# ---- Cube 计算粒度 ----
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fractal: int = 16 # 16x16x16 基本块
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# ---- 派生量 (属性) ----
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@property
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def q16(self) -> float:
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"""单核 Cube BF16 峰值算力 (FLOP/s)."""
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return self.cube_peak_tflops * 1e12 / self.aic_num
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@property
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def q_aiv(self) -> float:
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"""AIV 向量求和吞吐 (元素/s), 64 核合计."""
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return self.aiv_num * self.aiv_fp32_per_cycle * self.aiv_freq_ghz * 1e9
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@property
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def bw_pc(self) -> float:
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"""单核 GM 带宽份额 (Byte/s) = W_GM / C = 50GB/s."""
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return self.bw_gm / self.aic_num
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@property
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def bw_l2_pc(self) -> float:
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"""单核 L2 带宽份额 (Byte/s) = W_L2 / C ≈ 162.5GB/s."""
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return self.bw_l2 / self.aic_num
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@property
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def r16(self) -> float:
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"""16bit 位宽平衡点算存比 R_16 = Cube峰值 / (GM带宽/2B) ≈ 607.5 FLOP/元素."""
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return self.cube_peak_tflops * 1e12 / (self.bw_gm / 2)
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@property
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def min_core_num(self) -> int:
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"""确保高带宽利用率的并行搬移核数下限."""
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return round(self.min_core_num_ratio * self.aic_num)
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@property
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def t_cmd(self) -> float:
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"""T_cmd (秒)."""
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return self.t_cmd_ns * 1e-9
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@property
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def l0c_elems(self) -> int:
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"""L0C 容量 (fp32 元素数) = 65536."""
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return self.l0c_bytes // 4
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ASCEND950PR = NpuSpec()
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