Collection: Power Supplies

Which power supply do you actually need?

Most PC builders pick a PSU by wattage alone, but the number on the box is the least interesting spec. What changes between tiers is the internal design. Entry-level units, typically 80 Plus Bronze, often use a group regulated topology, where the 12V rail is generated first and the 5V and 3.3V rails are derived from it by a less precise method. They also tend to use smaller heatsinks, lower temperature rated capacitors and sleeve bearing fans. They run fine on modest hardware, but they cope poorly with sharp power spikes and age faster in a warm case.

The sweet spot is a quality 80 Plus Gold unit from 750W to 1000W. These almost always use an LLC resonant primary stage with DC-DC conversion for the minor rails, which gives tighter voltage regulation and lower ripple. They also have Japanese or high-grade capacitors, fluid dynamic or similar bearings, and a proper 10-year warranty. Enthusiast lines (Platinum and Titanium) add a bit more efficiency, often a semi-passive fan mode that holds up under load, and better transient handling. The efficiency gain from Gold to Platinum is only a couple of percentage points, so on a 500W gaming load you're saving a few watts of heat. That is where diminishing returns kick in. Spend the extra on build quality and warranty, not the badge.

As a rough guide, current mid-range GPU builds sit comfortably on 750W, high-end cards want 850W to 1000W, and flagship GPUs with a high-end CPU are safer on 1000W to 1200W.

Upgrading and technical nuances

For modern systems, look for ATX 3.1 units with a native 12V-2x6 connector. ATX 3.0 and 3.1 supplies are built to handle GPU power excursions of up to twice their rated wattage for very short bursts. That matters because current high-end Graphics Cards / GPU can spike well past their rated board power for fractions of a millisecond, and an older design can trip its over-current protection and shut the system down mid-game. ATX 3.1 also tightens hold-up time, which gives the PSU a little more ride-through if mains power briefly sags.

Native 12V-2x6 is better than using an adapter. An adapter adds extra connections and bulky cables, and every extra junction is another place for resistance and heat. If you're upgrading an older PSU, check that the modular connectors are correct, because the cable pinouts on the PSU end are not standardised across brands. Never mix modular cables between brands or even between series from the same brand. That's a classic way to fry a drive or a motherboard.

For benchmark series, the Seasonic Focus GX and Corsair RMx are the dependable sweet-spot choices. The be quiet! Straight Power and MSI MAG A-GL (ATX 3.x) lines also hit that mark. Step up to Seasonic Prime, Corsair HXi or ASUS ROG Thor if you want Platinum or Titanium efficiency, digital monitoring and quieter fan curves. On the budget side, Cooler Master MWE Gold and Corsair CX are fine for lighter builds, but I'd avoid them paired with a power-hungry GPU.

Platform doesn't change the PSU requirement much. AM5 and LGA1851 Motherboards still use a 24-pin ATX and one or two 8-pin CPU connectors. High-end boards with heavy VRMs may want two EPS leads, so check your PSU has them. A CPU and processor running at its full power limit can pull more current than you'd expect, so don't size only for the GPU.

Practical things to check

Start with physical size. Most are standard ATX, but compact cases often need SFX or SFX-L, and a few need SFX with extra-short depth. Check the PSU length against your case spec. Modular cables need extra space behind the plate, and thick 12V-2x6 cables need bend room. Leave at least 35mm of straight run before any bend at the GPU end, as sharp bends near the connector put stress on the pins. Check the PSU shroud and cable space in your Computer Cases, and make sure the fan has some room to breathe. Bottom-mounted PSUs should have their fan facing down to a filtered vent if the case allows it. If it doesn't, face it up into the case.

Next, count your connectors. You'll want the right number of PCIe 8-pin or 12V-2x6 leads, enough SATA power for your drives, and EPS leads for the CPU. A decent set of Cables & Connectors can fill gaps, but only buy cables made specifically for your PSU model.

For thermals, sustained load matters more than the peak rating. A PSU rated at 50°C continuous will hold its output in a warm Australian summer, but a budget unit rated at 40°C might not. Airflow from your Fans, Heatsinks & Cooling setup also affects PSU temperature. A PSU in a stuffy shroud with no vent will run hotter and louder. Finally, check that your wall socket and power board can handle the draw. Don't daisy-chain cheap boards for a high-end system.

Brands and local warranty

Good brands in this category include Corsair, Seasonic, be quiet!, MSI, ASUS, Cooler Master, Thermaltake, Antec and Gigabyte. Many of these are OEM'd by the same few factories (Seasonic, CWT, Super Flower, FSP), so the brand name matters less than the specific model and its platform.

Warranty is worth taking seriously with a PSU, since a failing unit can take other components with it. Buying from an Australian retailer means you deal with local support and get Australian Consumer Law protections, rather than posting a unit overseas and waiting weeks. Keep your invoice, and check the warranty terms for the model, since 7 to 12 years is common for quality units. Browse the full ATX Power Supply range for current options.

Frequently asked questions

How much wattage do I really need?

Add up your CPU and GPU peak power, add about 100W for the rest, then leave 20 to 30 percent headroom. Most gaming builds with a mid-range GPU are happy at 750W. High-end builds are better at 850W to 1000W.

Is a higher wattage PSU less efficient at low loads?

Slightly, since efficiency curves peak around 40 to 70 percent load. In practice, a decent Gold unit stays efficient at idle, and the difference in power use is small.

Can I reuse my old PSU in a new build?

Sometimes. If it's a quality unit within warranty and has the right connectors, yes. If it lacks a native 12V-2x6 or modern transient handling, it's a risk with a high-end GPU. Don't reuse modular cables from another PSU.

Is ATX 3.1 worth it if I have a lower-power GPU?

Often, yes, because the price gap is small and it makes future upgrades easier. The better transient handling also helps stability.

Do I need Platinum or Titanium?

Not for most people. They help if you run a heavy load 24/7 or want the best fan behaviour, but a well-built Gold unit is the better value for gaming.