Question 1

Why do I need headroom on my PSU?

Accepted Answer

A 20% headroom buffer ensures your PSU runs efficiently (80-90% load is the sweet spot for most PSUs), handles transient power spikes, and leaves room for future upgrades.

Question 2

What happens if my PSU is too small?

Accepted Answer

An undersized PSU can cause random shutdowns, system instability, boot failures and in extreme cases permanent damage to components. Always size up rather than down.

Question 3

Does 80 Plus certification matter?

Accepted Answer

Yes. 80 Plus Gold or higher rated PSUs waste less energy as heat, run quieter and typically use higher-quality components. They also lower your electricity bill over time.

Question 4

How much power does a modern GPU need?

Accepted Answer

Mid-range GPUs (RTX 4060 class) draw about 150-170W. High-end cards (RTX 4080/4090) can draw 300-450W under load, with brief spikes even higher.

Question 5

Should I get a modular or non-modular PSU?

Accepted Answer

Modular PSUs let you connect only the cables you need, improving airflow and cable management. Semi-modular is the best value option for most builders.

PC Power Supply (PSU) Calculator

Frequently asked questions

PC Power Supply (PSU) Calculator

Frequently asked questions