Computer Power

Last updated Nov 8, 2022 Edit Source

Dissipated only when computation is performed

Due to leakage current and dissipated whenever the system is powered on Thus, it is possible that heat reducing solutions like a heat sink can help to reduce powe consumption.

When voltage is reduced, the threshold that is used to differentiate between a logic 1 and logic 0 output will be reduced. If this threshold is small, a high frequency will be more prone to noise that could alter the output.

1. Component design
2. Power gating: shutting down unused components
3. Clock gating: reduce unnecessary switching
4. Reduce data movement, number of memory access and register transfer

Case 1: Change in voltage = 3.3 - 3 / 3 = 10% i. New frequency = $1.1 * 300 = 330 MHz$ Change in dynamic power = $\frac{3.3^2 \times 330 }{3^2300} - 1 = 33.1%$ ii. Change in static power = 10% iii. Perf is directly proportional to freq. Change in perf = 10% iv. $$ \begin{aligned} &\text{Perf is = 1/Time} \\ &\text{Dynamic energy} \\ &\text{Increase in performance by 10% means that the change in time is 1/1.1}\\ &\text{Consumption change} = 1.331 P * 1/1.1T - PT = 21%increase\\ &\text{Static energy:}\\ &1.1P * 1/1.1T - 1 = 0% \end{aligned} $$

Case 2: i. $\frac{3.3^2 - 3^2}{3^2} = 21%$ ii. 10% increase iii. No change in frequency so no change in performance iv. Dynamic energy consumption: 21% increase Static energy consumption: 10% increase