Modular vs Non-Modular Power Supplies
On a fully modular power supply every cable detaches, so you connect only the ones your build uses. On a non-modular unit every cable is permanently attached and the ones you do not need have to be tucked away somewhere inside the case. Electrically the two are identical: modularity changes cable management and nothing else about how the unit performs.
Modular is a convenience feature you are buying, not a performance one. In a small or glass-fronted case it earns its money easily, because there is nowhere to hide a bundle of unused cables. In a roomy case with a shroud, a non-modular unit from a good line does the same job for less, and the money is better spent on wattage headroom or a higher efficiency grade.
The difference on paper
These hold for the category as a whole, independent of any one unit.
The difference in practice
How the two actually differ across units you can buy today, rather than what the standard permits. Measured across 327 Fully modular and 70 Non-modular units with a live offer at the retailers we track, and updated daily.
Depth and noise are quoted against their own samples because neither is published for every unit, and assuming a figure for the ones that do not publish one would change the answer.
The picks on each side
The cheapest unit on each side, and the cheapest one that clears a bar worth clearing: at least 40 of 100 on the quality score. Recalculated daily from live prices.
Fully modular
Non-modular
Best all-round
No Non-modular unit in stock clears the score bar, which is itself worth knowing about the category.
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Common questions
What is a semi-modular power supply?
The cables every build needs, the motherboard and CPU power, are permanently attached, while the optional ones, PCIe and SATA, detach. It captures most of the tidiness benefit for less than a fully modular unit.
Do modular cables affect performance or safety?
No. The extra connector adds a very small amount of resistance that no build will ever notice. The one real rule is never to reuse cables between different power supplies, even from the same brand, because the pinouts are not standardised.
Can I use custom cables with a non-modular PSU?
Not directly, since the cables are soldered in. You can add sleeved extensions that plug in between the fixed cable and the component, which gets the look without touching the power supply.
Keep going
Browse Fully modular units or Non-modular units with every filter, read up on how much wattage you need, or start from the power supply comparison hub.