Modular Power Supplies Less Efficient Say Makers

It's all about power efficiency these days.

Up until the last few years, few paid any attention to the little box that actually powers a PC--the power supply. Now with certifications like the 80-Plus, we're able to at least distinguish efficient power supplies from the rest of the pack. But even with 80-Plus, more and more power supplies are jumping on the bandwagon, so while product quality goes up overall, things are still not where manufacturers want them to be.

There's more detail to power supplies than can fit in the scope of this article, but we spoke to several power supply manufacturers at Computex and the focus customers put on their units.

Despite modular power supplies being a hot product, don't be quick to grab the up-take. The companies we spoke to told us that modular power supplies are less efficient than those that have their cables hard-wired. The reason being that the extra connection you make, adds resistance, and hence, increases heat and reduces efficiency.

Enermax, Seasonic, and Corsair all told us that if you're looking to maximize efficiency, go for a non-modular PSU.

Are the differences great? No one gave us any hard numbers, but they did indicate that the numbers are measurable. PC Power & Cooling, now part of OCZ, says the same thing:

Due to their look, convenience, and cost savings for manufacturers, modular plugs have become a popular power supply feature. Unfortunately, there has been little or no discussion of the impact of this feature on overall performance and reliability. The fact is, modular plugs limit power by adding to electrical resistance. The voltage drop can be as much as would occur in 2 feet of standard wire. Worse yet, modular plugs utilize delicate pins that can easily loosen, corrode, and burn, creating the potential for a major system failure. That's why professional system builders specify uninterrupted wire!

So in the end, you have to choose: do you go with a modular PSU for cable management and appearance, or do you spring for a hard-wired PSU?

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  • B-Unit
    Glad to see the major players getting behind this. I read a couple of articles online talking about this over a year ago and have avoided purchasing or recommending modular PSUs since.
  • stray_gator
    PCP&C always discouraged modular psu's - which they also didn't make.
    Hearing similar claims from other manufacturers (some of which sell mainly modular units), though, give them more weight and credibility.
    I'd still love to see some hard numbers, anyway.
  • theone1
    If two connectors and pin (male female) add 1 ohm (total) then for a 20-40A current you loose 20-40 Watts.