A system technician is calculating the minimum recommended power supply unit (PSU) wattage… — CompTIA A+ (Core 1 & Core 2)

A system technician is calculating the minimum recommended power supply unit (PSU) wattage rating for a multimedia editing workstation. The workstation components have the following maximum continuous power requirements under full load:

- Central Processing Unit (CPU): $95\text{ W}$
- Dedicated Graphics Card (GPU): $210\text{ W}$
- Hardware Capture Expansion Card: $45\text{ W}$
- 10GbE Network Adapter Card: $35\text{ W}$
- Motherboard, System RAM, Storage Drives, and Cooling Fans: $65\text{ W}$

According to IT best practices, a power supply should be sized so that total maximum system power consumption does not exceed $75\%$ of the PSU's rated continuous output capacity. What is the minimum rated output wattage required for the replacement PSU?

Answer: 600 W

Answer

600 W

To calculate the minimum required power supply wattage rating, first sum the continuous power draw of all components:

95\text{ W}\text{ (CPU)} + 210\text{ W}\text{ (GPU)} + 45\text{ W}\text{ (Capture Card)} + 35\text{ W}\text{ (NIC)} + 65\text{ W}\text{ (Motherboard/RAM/Storage/Cooling)} = 450\text{ W}

. To satisfy the guideline that total consumption must not exceed

75\%

(

0.75

) of the rated PSU capacity, divide the total wattage draw by 0.75:

\frac{450\text{ W}}{0.75} = 600\text{ W}

Step-by-Step Solution

Calculate the total power consumption of all workstation components under full load.

95\text{ W} + 210\text{ W} + 45\text{ W} + 35\text{ W} + 65\text{ W} = 450\text{ W}

total continuous power draw.

Proper PSU sizing requires accounting for all active internal hardware, including the CPU, GPU, all PCI Express expansion cards, drives, memory, motherboard, and cooling accessories.

Divide the total continuous power consumption by the targeted maximum load percentage (0.75).

\frac{450\text{ W}}{0.75} = 600\text{ W}

minimum rated power supply output capacity.

Operating a power supply at or below 75% capacity ensures optimal energy conversion efficiency, reduces heat production, and provides essential safety headroom for transient power draw spikes.

Key Concept

Power supply wattage sizing calculations based on total system component power draw and target continuous load headroom guidelines.

Estimated Time:1m 30s

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