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Two PSU's for Dual 8PIN.

post #1 of 27
Thread Starter 
Pretty simple quick question; do I need identical PSU's for my dual 8 pin cpu inputs on my Classified e760? The only problems I can see is the psu rails wouldn't be the same, possibly causing power issues. Other than that, it seems like even a little extra power will help stabilize things.

Main PSU is HX650, second would be 400CX and would just be using the 8 pin.

I would jump the 400CX (green-black) first, power it on, then just power on the system like normal.

Going to be doing some DICE runs Tuesday and would like a little extra power to possibly help it out.

Okay, to clarify since a lot of you seem to be misunderstanding my question:

There is no doubt that I can run with a single 8 pin, my question is NOT do I need the second 8 pin. The question is, can any harm come from using the second 8 pin with a PSU that isn't identical to the first.

If no harm can come, then I will use it. Even if it gives me 1 more mhz on my BCLK, then that's great, if it does nothing, then oh well it didn't hurt me either.
Edited by fl0w3n - 5/15/11 at 4:34pm
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post #2 of 27
As long as the system can't pull more that the second set of 8 pin pcie can give then you are a-ok! mobo only cares about what's being provided not how much it potentially can :-).
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post #3 of 27
This is a really bad idea... even if you got the two PSUs to come on at the same time, they would produce slightly different voltages which would create a large current flow going from to the other. Probably through your motherboard. Not to mention ground loops which might create enough noise to be a problem...

Motherboards and PSUs are not designed for this kind of operation, and you're liable to melt something or at least trip something's protection doing it.
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post #4 of 27
What PSU's come with dual 8 pins for the CPU/motherboard? I really can't think of that many. Mine didn't
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post #5 of 27
Thread Starter 
Quote:
Originally Posted by appleg33k85 View Post
As long as the system can't pull more that the second set of 8 pin pcie can give then you are a-ok! mobo only cares about what's being provided not how much it potentially can :-).
Quote:
Originally Posted by Birthday Attack View Post
This is a really bad idea... even if you got the two PSUs to come on at the same time, they would produce slightly different voltages which would create a large current flow going from to the other. Probably through your motherboard. Not to mention ground loops which might create enough noise to be a problem...

Motherboards and PSUs are not designed for this kind of operation, and you're liable to melt something or at least trip something's protection doing it.
Lol interesting replies...

Birthday, you're saying that I do need identical power supplies then?
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post #6 of 27
Thread Starter 
Quote:
Originally Posted by thealex132 View Post
What PSU's come with dual 8 pins for the CPU/motherboard? I really can't think of that many. Mine didn't
EVGA's SR-2 PSU might.

None others do. The point of having two 8 pins is for two separate PSU's. I just didn't know if both of them had to be identical or not.

Almost every benching rig I've seen uses two PSU's, and sometimes three. Usually they are the same units though.
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post #7 of 27
My Antec TPQ 1200w did. 8pin then a 4pin + 4pin.
post #8 of 27
just use 1 8 pin.


You need to be using like 600w+ (or something close to that) to warrant the use of 2.
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post #9 of 27
Thread Starter 
Quote:
Originally Posted by MoonPig View Post
My Antec TPQ 1200w did. 8pin then a 4pin + 4pin.
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post #10 of 27
Thread Starter 
Quote:
Originally Posted by reflex99 View Post
just use 1 8 pin.


You need to be using like 600w+ to warrant the use of 2.
If I'm pushing 1.65 on water, I don't see 1.8v too far off on DICE...


holy ninja edit...


Triple ninja edit...
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