Where to draw power from?

ktec

ktec

New Member
Hi,
So my 500w OCZ psu has two 12v rails each at 18a (but both cant be 18a max at a time since that would put it over 500w). 12v1 is for the M/B and PCI-e connector. Rail 12v2 is for CPU and accessory(im guessing molex and HDD).

My question is, lets say I have a video card that draws too much current for the 12v1 pci-e connector. Would it be possible for it run correctly on using a molex to pci-e connector? Would one rail have more available power vs the other rail?

Personally I think the CPU draws more power than the M/B, hence leaving less available power on that rail, but I am not sure.
 
One rail is dedicated for the CPU and the other for the system. The 18 amps is just what any one rail can pull without tripping. You dont add the rails together to get the total of amps. Unless its a true dual rail which the OCZ is not. What OCZ 500W, model number?
 
im not sure if you are serious with your reply...i already stated exactly what you said. Did you even read my question?
 
I understood and answered your question. One rail is ((dedicated for the CPU)). So the molex and PCIe connector pulls off the same rail, makes not difference which one you use.
 
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ktec said:
Hi,
12v1 is for the M/B and PCI-e connector. Rail 12v2 is for CPU and accessory(im guessing molex and HDD).
Click to expand...

Rail 1 = mobo and PCI-e
Rail 2 = CPU and accessory
So with this PSU pci-e and molex are on different rails
 
ktec said:
Rail 1 = mobo and PCI-e
Rail 2 = CPU and accessory
So with this PSU pci-e and molex are on different rails
Click to expand...

Accessory, how do you come to the conclusion thats the molex connectors? On some boards the CPU fan header and if it has it, the Northbridge fan header runs off the CPU power connector. Which I think thats what accessory means. The 20/24 and SATA/Molex/PCIe and if it has it a floppy power connectors all run off the other rail. That is unless OCZ isnt going by ATX standards.

If you want to argue about it, show my something from OCZ thats says accessory means the molex conectors.

Edit. Think you are right. Thats one weird power supply. Makes having a CPU power rail completely pointless.


  • 12V1 rail (solid yellow wire): Main motherboard connector and video card auxiliary power connector.
  • +12V2 rail (yellow with black stripe wire): ATX12V connector, SATA power connectors and peripheral power connectors.
http://www.hardwaresecrets.com/article/OCZ-StealthXStream-500-W-Power-Supply-Review/798/6
 
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It sort of makes sense, they are splitting the 2 big power drawers; the CPU and the Video card and putting them on separate rails.
 
More often than not, the "rails" are actually cables and their connectors. Internally, it's probably a single rail, which means it doesn't matter which cables you use, especially in this wattage range. Once you go to 800W and above, you start to see some true multi rail units, and then it will matter which cables you use. In that case they are normally marked (I think)
 
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