Modular Power Supplies Less Efficient Say Makers

[papaechoromeo]

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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?

more info here

[Seiryuu]

this would make a buzz...

[centax error]

is there a review wherein they have tested numbers of popular modular PSU's that shows how much resistance and voltage drops? numbers would be somewhat more interesting to look at

[CeeJay]

this is not new, there had been discussions about resistance and power loss with modular cabling. at the end of the day. well built modular psu's perform as good as non-modular PSU's.

one of the reasons professional system builders specify uninterrupted cabling: price... non-modular psu's are cheaper, and their user base do not need modular cabling.

[CeeJay]

old but related to the topic:
Modular Power Supplies: The Reality of the Resistance. Motherboards.org

[COMCAM]

For me gamay ra kaayo na percentage

[centax error]

see, numbers are always better otherwise the whole thing is misleading

[reishoto]

too little to get my 5seconds of attention..

good to know, but not much of a concern...

[jiro]

propaganda?

also gamay ra kaayu diference, i look at the source of this quote and found it came from PCpower and cooling. a company that doesnt make modular psu.

Source of the quote-
Power Supply Myths Exposed!


September 2005 • Vol.5 Issue 9
more info - Power supplies and cooling devices from PC Power and Cooling, Inc.

CPU: Modular power supplies seem to be gaining a lot of traction in the market, but PCP&C doesn't make any modular designs. Why?

Dodson: Yeah, it's real popular, but the industry hasn't done anything to educate people about modular plugs. The pins that are used in the modular plugs have a very low capacity to pass current. You're losing power through those pins. It's electrical resistance between the male and the female part of the pin, to the extent that the voltage drop in just the pins is equivalent to about two feet of wire. The effect is that modular power supplies, everything else being equal, are capable of about 10% less power than power supplies without modular plugs. And that's under ideal conditions. In real life it gets worse because the pins loosen, corrode, and burn. Over time the resistance builds up. A year down the road, a guy could be running his system and all of a sudden it stops working reliably, and he has no way of knowing that the reason is because the pin inside that modular plug has become corroded or burned. This technique has been out for about six months, but people are going to find that the reliability is a massive failure point. Also, especially given the way people pull their harnesses around and tie them down, it creates a lot of stress on those pins. So instead of the pins having full 100% contact surface to surface, in most cases those pins are only touching maybe 10% or 30% of their surface area. What's rated for 5A going through those pins, in reality if the pins aren't making good contact, your rating's down to maybe 3A, and with that much constriction, those pins just heat up, and it gets worse. For real pros in the industry, no way would they specify that kind of arrangement. This is a consumer-oriented gimmick.

[poldopunk]

this is actually the first comment from PSU manufacturers with regards to going modular. the first early statements got no backing from OEMs but this one caused a stir because the statement is coming from the manufacturer themselves.