Everything you need to know about power supplies

Ripple, noise, power factor correction
Other factors you’ll read about but which are less important are ripple, noise, and PFC. Noise and ripple (or regulation) are used to describe the cleanliness of a rail’s output, how much the voltage fluctuates and how tightly the rails adhere to their rated voltages. Some say overclocking can be limited by PSUs with poor results here, but as long as they stay within limits when under load you’re fine. PFC is a little complicated given the space to elaborate here, but lets just say it’s good if it’s as close to ‘one’ as possible, and most PSUs do this just fine.

Modular versus not
An old wives tale used to put modular PSUs at a disadvantage, stating that the extra resistance induced as a result of the modular connections was a cause for instability. Poorly made modular PSUs could also be problematic by creating loose connections, adding another level of complexity to diagnosing power problems.

In truth, when modular PSUs first appeared, these tales were based in fact, with some badly made modular PSUs giving rise to the wisdom that modular wasn’t the way to go.

But this isn’t the case anymore. Any good PSU with modular outputs usually ensures both tight fitting and snug connections, and doesn’t suffer any sort of issues related to increased resistance – after all it’s just another connection, same as plugs on the end of the cables.

So don’t be afraid to go modular. Additionally, modulars provide the benefit of being able to hook up only the cables you need, in turn reducing cable clutter and ultimately improving airflow within a case.