Quick Answer

SA builders oversize PSUs mainly because GPU transient spikes and rising GPU power draw make extra headroom genuine insurance, not just caution. A 650W unit suits an RTX 5060, but builders often fit 750-850W to leave room for a future GPU and to keep the unit quiet and efficient. The trick is sensible headroom: aim for the GPU at 50-65% of the PSU rating, and always pick ATX 3.1, from around R1,200 at Evetech.

Why the Habit Makes Sense Here

Replacing a PSU later means rebuilding cables and risking the warranty, and shipping a single part back and forth in South Africa is slow. So builders buy once and buy slightly big. With ATX 3.1 cards spiking hard, a touch of headroom also prevents the random shutdowns that a borderline unit causes. It is a rational response to real transient behaviour, not paranoia.

Sensible Oversizing vs Overspending

Sensible: an 850W unit for a 5070 Ti rig you plan to upgrade to a 5080 later. Overspending: a 1200W unit on a 5060 build that will never need it. Match these tiers: 650W for RTX 5060, 750-850W for RTX 5070/5080, 1000W+ for RTX 5090. A quality 850W ATX 3.1 unit runs around R2,000 at Evetech, which is fair insurance on a R30,000 build.

Efficiency and Noise

A PSU runs most efficiently and quietly around half load, so a 650W card on an 850W unit stays cool and silent. Push a 650W unit to 90% and it gets hot and audible. That efficiency sweet spot is a legitimate reason SA builders lean one tier up.

FAQ

Is it bad to oversize my PSU?

No, within reason. A unit running near half load is cooler, quieter, and more efficient, and it leaves room to upgrade. Only a wildly oversized choice, like 1200W on a 5060, wastes money.

What PSU should I buy if I plan to upgrade my GPU?

Buy for the GPU tier above your current one. If you run a 5070 now and may move to a 5080, an 850W ATX 3.1 unit (around R2,000 at Evetech) covers both without a second purchase.

Does a bigger PSU use more electricity?

No. A PSU only draws what the system needs, so a 1000W unit powering a 400W system still uses about 400W. The rating is a ceiling, not a constant draw.

Pick a PSU one tier above your current GPU's needs so a future upgrade is drop-in: 850W ATX 3.1 covers a 5070-to-5080 path, and the unit stays cool and quiet at half load.