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Dual PSU - what components are safe?

  • Power Supplies
  • CPUs
  • Components
  • Power
Last response: in Components
May 5, 2010 7:04:44 PM

Hi all, I've had a look through the forum but couldn't find a definitive answer... what is safe to dual PSU?

While troubleshooting my current system, my main (500W) PSU's 4-pin CPU connector has reached the end of it's life (yes it's embarassing but my god was that an unusually tight plastic connector)

I've already successfully supplied separate power to my drives, but would it be a stupid idea to supply 12v CPU power from an old 300W PSU that I have lying around?

More about : dual psu components safe

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May 5, 2010 11:07:36 PM

It is typically safe to use more than one power supply, what isn't safe is not knowing what went wrong with 4pin cpu connector. If the 4pin failed which is 12v and it wasn't on a seperate rail then there is still something wrong with the 12v line in the main (500w) so using it is not safe. I'm not familiar with any power supply which puts the 4pin cpu connector by itself on a rail.
May 6, 2010 12:31:27 AM

Hi, thanks for the reply

The 4-pin failure was a physical failure, the wires came loose from the plastic connector, no previous power/shorting issues.

I'm currently using it with no problems in an older motherboard that does not require the dedicated 4-pin (my main board won't POST without it). The older board takes a 20-pin connection - the PSU is 20+4.

I've seen a few posts discussing two power supplies possibly interfering with each other, causing ground loops and other current issues, say when used to power motherboard and graphics card respectively. Has anybody here powered/powers a CPU-dedicated 12v with a separate PSU?