06 DVFS 功耗、能效比与热阻定量模型¶
1. 芯片总功耗与结温(Junction Temperature)耦合模型¶
\[\begin{cases}
P_{total}(V, f, T_j) = \alpha C V^2 f + V \times I_0 \cdot \exp\left(\frac{q(V - V_0)}{k T_j}\right) \\
T_j = T_{ambient} + P_{total} \times \theta_{ja}
\end{cases}\]
- \(\theta_{ja}\):芯片硅片到环境空气的总热阻(典型风冷 \(\approx 0.12\text{ °C/W}\),先进液冷 \(\approx 0.04\text{ °C/W}\))。
graph LR
subgraph PowerThermalCoupling["功耗与温度正反馈循环"]
HighPower["高工作功耗 (700W)"] --> HighTemp["结温上升 (T_j -> 90°C)"]
HighTemp --> HighLeakage["漏电电流指数激增 (+35%)"]
HighLeakage --> HighPower
end
2. P-States 调频调压节能定量对比¶
| P-State 档位 | 核心频率 (GHz) | 供电电压 (V) | 动态功耗 (W) | 静态漏电 (W) | 总功耗 (W) | 适用场景 |
|---|---|---|---|---|---|---|
| P0 (Max Boost) | 2.1 GHz | 0.95 V | 580 W | 120 W | 700 W | LLM 训练与密集推理 |
| P2 (Balanced) | 1.5 GHz | 0.80 V | 290 W | 60 W | 350 W | 批处理轻载渲染 (能效比最优) |
| P8 (Idle) | 0.3 GHz | 0.65 V | 15 W | 15 W | 30 W | 桌面待机与轻量显示 |