I am trying to upgrade the power supply in an older Gateway 450 with the Pentium 3 processor.  The original power supply has a wire for -5 vdc supply to the mother board.  The new ANTEC SP500 does not have this supply.

Is there a need for the -5 vdc supply on the Pentium3 and its associated hardware?  Will installing the supply without this cause damage to the system?

Thanks for your help.

Chris.Is the "older Gateway 450" a Pentium II or III?Sorry, I wrote Pentium 3.

It is a Pentium III 450 mHz on a Jabil BX motherboard.

Support documents indicate that the board "must have standard ATX 20-pin power connector"

Chris-5V is optional for the PCI-bus only.  Antec SP500 will work with no problem, assuming it fits in the case you have.  Make sure the Gateway is not a Micro-ATX.  ATX has 4 mounting screws, Micro-ATX has 3 mounting screws.

SP-500

Antec says:
"...24-pin power connector with detachable 4-pin section for backwards compatibility with ATX 20-pin motherboards..."Thanks for the info.  It is a full tower case, with a 4 hole mounting CONFIGURATION for the supply.  It may need some slight modding to adjust the opening, but I have not removed the old supply yet to verify if there are any adapter plates in place.

I remember reading somewhere that the -5 v is optional, but it's good to have a second opinion.

Chris.If the case is ATX, any ATX power supply will fit.Unless it is a Dell or Gateway. Their PSU are proprietary. Dell has some of the voltage lines switched and Gateway are sized differently.As a follow-up for those interested, I spoke with ANTEC support and they ASSURED me that connecting the supply would not hurt anything.  If the motherboard requires the -5v signal, the computer just will not boot.

During a more careful examination of the Gateway support documents, I located a page which clearly states the the -5v and -12v signals are not used by Gateway motherboards, but are legacy connections used by older floppy controllers and built-in SERIAL ports.  I will try hooking up the supply and post my results.

Thanks again for everyone's replies.

Chris.As a follow-up for those interested, I spoke with ANTEC support and they assured me that connecting the supply would not hurt anything.  If the motherboard requires the -5v signal, the computer just will not boot.

During a more careful examination of the Gateway support documents, I located a page which clearly states that the -5v and -12v signals are not used by Gateway motherboards, but are legacy connections used by older floppy controllers and built-in serial ports.  I will try hooking up the supply and post my results.

Thanks again for everyone's replies.

Chris.