multiple power supplies

What are the issues that exist for using multiple power supplies? Example: Using one for the motherboard and hard drives and another for CD, DVD and CDRWs. I have a number of power supplies from 486s on up and want to know if they can be used. Thank you.

I had a problem with a motherboard going out than a power supply (smoking). I has thinking that by placing the hard drives and CD drives on separate power supplies, there will more than enough power leftover for the motherboard to support a few cards - modem,old scanner scsi card,firewire. My wife left the computer one night and it did not work any more. Oh well - another dead computer.

<P ID="edit"><FONT SIZE=-1><EM>Edited by TRC on 12/20/02 01:30 PM.</EM></FONT></P>

I believe that they can be used if they are older power supplies. All the newer power supplies with the ATX standard are powered on by the motherboard so they can only give power when they are the one connected to the Mobo. That means that all your other components that are plugged into other power supplies won't get any power. I have heard there are ways around this, but nothing that is too simple.

Try testing if the power supply is old enough by plugging in a fan to the PSU without it connected to the mobo and if it works, I think you would be safe connecting your HD's to a second power supply. The only other issue is where you would put the other power supply? Do you plan on leaving your case open?

I believe that the voltages for the Hard drives have stayed the same since 486's. voltages for motherboard connections have changed for sure so you wouldn't want to use an older PSU for the motherboard at all (assuming it would fit).

Well actually it is really simple. All I did was connect the powergood signal with a ground on the second PSU and the connect the poweron with his ground wires with that of the first PSU powering the mobo. The biggest problem was modding my case to fit two PSU.

<A HREF="http://www.waterkoeling.nl/files/voeding.gif" target="_new">Here is a picture that shows which cables should be connected with eachother.</A>

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