PSU Buying Guide 2026: How Much Power Supply Do You Actually Need?

The power supply unit (PSU) is the least glamorous part of any build, but it's the one component every other part depends on. Get it wrong and you risk instability, wasted money, or in the worst case, damaged hardware. Here's what actually matters when choosing one in 2026.

How much wattage do you need?

Wattage should be based on your GPU and CPU combined, not guesswork. As a rough guide:

  • 450-550W - entry-level builds with a mid-range CPU and no discrete GPU, or a light GPU like an RTX 4050-class card.
  • 650-750W - most gaming builds running a mid-to-high-end GPU (RTX 4070/4080-class) paired with a modern CPU.
  • 850W+ - high-end builds with power-hungry flagship GPUs, overclocked CPUs, or multiple storage drives and extra fans/RGB.

A good rule of thumb is to add up your components' rated power draw and leave 20-30% headroom, both for stability under load and so the PSU runs well below its maximum, where it's most efficient.

Efficiency ratings: what 80 PLUS actually means

You'll see PSUs labelled Bronze, Gold, Platinum or Titanium under the 80 PLUS certification. This measures how much power is wasted as heat rather than delivered to your components:

  • Bronze - around 82-85% efficient. Fine for budget builds.
  • Gold - around 87-90% efficient. The sweet spot for most gaming and workstation builds.
  • Platinum/Titanium - 90%+ efficient. Worth it for high-wattage or always-on systems where the running cost savings add up.

Modular vs non-modular

Modular PSUs let you attach only the cables you need, which makes cable management easier and improves airflow. Non-modular units are cheaper but come with a fixed bundle of cables you'll need to tuck away regardless of whether you use them. Semi-modular is a common middle ground, with essential cables (like the 24-pin motherboard connector) fixed and the rest detachable.

Don't skip on quality

A PSU is not the place to cut corners. A poor-quality unit can deliver unstable voltages, fail suddenly, or in rare cases damage connected components. Look for a solid warranty (5-10 years from reputable brands is normal) and avoid unbranded or unusually cheap units, especially at higher wattages.

Quick checklist before you buy

  • Total up your components' power draw and add 20-30% headroom
  • Aim for at least an 80 PLUS Gold rating for a good balance of efficiency and cost
  • Go semi- or fully-modular if cable management and airflow matter to you
  • Check your case has room for the PSU's physical size, especially in compact builds
  • Buy from a brand with a strong warranty rather than the cheapest option available

Getting the PSU right means one less thing to worry about, and it's a component that can comfortably outlast two or three GPU upgrades if you choose well the first time.

Ready to find the right power supply? Browse our power supplies to find the right wattage and efficiency rating for your build.

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