Power & Cooling

⚡ The power supply

The power supply (PSU) takes mains electricity and converts it to the steady low voltages each part needs. A good, reliable PSU protects the whole computer.

🔌 Watts and demand

Power is measured in watts. A powerful GPU can draw a lot; the PSU must supply enough for all parts, with some to spare. Phones and laptops use far less than big desktops.

🔥 Work makes heat

When the CPU and GPU work hard they get hot. If they get too hot they slow themselves down (thermal throttling) to stay safe — so good cooling keeps performance up.

🧊 Thermal paste & coolers

A thin layer of thermal paste between a chip and its cooler helps heat flow into the metal fins, which fans or liquid then carry away.

🌬️ Airflow and dust

Cool air should enter the front and hot air leave the back and top (hot air rises). Dust blocks airflow, so keeping vents clean keeps a computer cool — important in dusty conditions.

Key points

• The power supply converts mains electricity to what the parts need.
• Power is measured in watts; the PSU must supply enough for all parts.
• Working hard makes the CPU and GPU hot.
• Too hot and they slow down to stay safe — that's thermal throttling.
• Thermal paste helps heat flow from the chip into the cooler.
• Fans or liquid then carry the heat away.
• Cool air in the front, hot air out the back. Dust blocks airflow, so clean the vents.

Try it for real: Heat check

• Use a monitor app to see the CPU temperature while idle.
• Do something heavy (a big download, a game, many tabs) and watch the temperature rise.
• Look at the computer's vents — are they dusty? Should they be cleaned?