Modular PSU question, probably stupid!

d3vovus

Junior Member
Sep 1, 2013
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Hey guys I have a Corsair HX750w modular power supply that is powering my i5 rig that has two hard drives, one CD drive and a GTX 650 Ti Boost graphics card, and 5 fans all connected to a fan controller.

Out of the 10 or so cables that came with the HX750, I only used 3 to power everything in my PC. Am I overloading certain rails or components within the PSU by not "spreading" out the load using more modular cables, or does it not matter either way?
 

Azix

Golden Member
Apr 18, 2014
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Yeah only problem would be overloading connectors or something. Doubt that would happen.
 

Micrornd

Golden Member
Mar 2, 2013
1,364
227
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Yeah only problem would be overloading connectors or something. Doubt that would happen.

No, any cable supports full current on the # of connectors it has.

Perhaps you misunderstood Azix. :\
Any connector will attempt to supply any amount of current demanded of it.
Connectors have no inherent current limiting abilities (beyond their own physical destruction) and can be easily overloaded if the "rail" can supply more current than the connector is capable of handling.

As an example, with this particular PS, 60+ amps are available on the 12v rail, so that current is available to all 4pin molex connectors on the power supply, even though it would melt the wires or connector if that much was attempted to be drawn from that connector.
 

mindless1

Diamond Member
Aug 11, 2001
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^ No I didn't misunderstand and no you don't understand.

It's not a matter of "attempt to supply any amount of current". I'm well aware that you could cause a short and exceed the current carry capability of the wire and connectors but that's not the relevant issue.

The relevant issue is that it is very hard if not impossible to plug devices into those connectors that cause excessive current. (with the exception of overclocking CPU or GPU). The current limit is the connector contacts themselves before the wire becomes a limit and no device plugged into a connector will use more than 6A per wire and contact.

Perhaps I should have worded it "Any properly designed cable supports full current on the # of connectors it has." There's nothing stopping a company from putting 20 4-pin molex connectors on the same group of wires except for what I mentioned, that they deliberately don't put enough connectors on the wire to allow for overloading it.

Any device that needs more current than a single connector contact can supply, has more than one connector contact, for example video cards and CPUs both have them, and both have one connector on the group of wires to each. You could cause an overload if you started adding Y-splitters on a connector to power more devices than the group of wires was designed to handle but not with only the connectors already on the wire group as it comes from the factory.
 
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Micrornd

Golden Member
Mar 2, 2013
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I totally agree.
In a perfect world, no one uses splitters, no one attaches excess pumps or TECs to molex strings.
Problem is most of us live in the real world where we've seen this stuff happen.

And, yes, had you said
Any properly designed cable supports full current on the # of connectors it has.
that would have been clearer.

But I still stand by
As an example, with this particular PS, 60+ amps are available on the 12v rail, so that current is available to all 4pin molex connectors on the power supply, even though it would melt the wires or connector if that much was attempted to be drawn from that connector.
as I have seen this happen more than onec.