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Old 03-25-2008, 10:46 AM   #11
jonnyGURU
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Power Supplies
 
Join Date: Oct 1999
Posts: 11,683
Default The splitting of the +12V rail

Quote:
Originally posted by: Ratman6161
I just ordered a Q6600 and Abit IP35-e. The rest of my components (including power supply) will be migrated from my existing system. My PS is an Ultra X-Finity 600 Watt. What can I say, it was cheap at the time! Its configuration looks like what you described as "old school", i.e.

"2 x 12V rails
* Original ATX12V specification's division of +12V rails.
* One rail to the CPU, one rail to everything else.
* VERY old school since it's very likely that "everything else" may include a graphics card that requires a PCIe connector.
* Typically only seen on PSU's < 600W. "

According to the manufacturer, 12v1 is 18 amp and 12v2 is 20 amp

The 12v cpu power connector has two 4 pin plugs that can supposedly be used together in an 8 pin socket. So, I'm assuming that those cpu power connectors are on their own rail? But the documentation doesn't say if its the 18 or the 20 amp going to the cpu.
If I had to guess, I would say the CPU is on the 18A rail since the PSU has to have enough power to do low end SLI.

Quote:
Originally posted by: Ratman6161It also has two 6 pin PciE power connectors, but with only two rails, I'm assuming that those are actually sharing with the molex connectors, right?
Right.

Quote:
Originally posted by: Ratman6161Anyway, my video card is a 7900GS, so not as power hungry as many. I have no desire for SLI and the motherboard I ordered doesn't support it anyway. Other than the CPU and video card, the system will have 8GB DDR2 800 ram, 1 SATA2 hard drive, 1 IDE hard drive, and a DVD burner, and thats it. As to over clocking, I'm shooting for 3.0 Ghz since at that speed I should be just overclocking the CPU and running everything else in spec.

So I think I should be fine with what I have as far as power supply goes. Can anyone give me a warm fuzzy that I'm not going to destroy my new cpu with insufficient power?
You should be fine. There's enough power on that +12V rail for a pair of Nv 6x cards or ATI 1950's, so one 7900GS is nothing.
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