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Sx 850 PCIe questions

Last response: in Components
January 24, 2013 7:30:42 AM

Hello everyone,
I have a somewhat beginner question about my current build as it's the first modular PSU I've used.

as the title states we are talking about a Cougar sx 850 PSU

Under the specs tab you will find the power chart that states 4 12v rails, two @22A and the other two @24A.
Here is the cable layout.
Here are the modular connections

what is getting me hung up is (if you look at the PSU there are 4 red connectors labeled 12v4 and 12v3, and from this I assume both rails 3 and 4 are powering that block of 4 connectors. The unit came with two red modular connectors for PCIe 6+2 pin cables for a graphics card.
The unit also has 2 PCIe 6+2 pin cables hard wired... which from the table above I can assume is powered by 12v2. (as the unit has the block of black connectors labeled as 12v1)

So I suppose my question to the forum is this;
Running dual EVGA 560 FTW+ cards in SLI (each requiring two 6 pin PCIe connections) I have a total of 4 PCIe 6+4 pin cables, two from the box labeled 12v3/12v4 and two that were hard wired from 12v2.

How do I power these cards properly? the two "red" connectors state 24A where the hard wired ones state 22A.

do I a) use both "red" (24A) connections on a single card and both 22A ones on the other

b) Use one 24A and one 22A for each card


c) try to get a hold of 2 more "red" PCIe cables for the second card.... It would seem to me that they built 4 "red" ports so you should be able to connect 4 "red" cables on those rails... however only two were included which makes me wonder if they did that for a reason.

More about : 850 pcie questions

January 31, 2013 5:14:01 PM

Your links aren't working for me. However, from the product's website and the blowup pics on Newegg's site, it appears that the PSU actually contains 2 more red PCIe headers than the company shows on their own website. The normal way to utilize the PCIe connectors is to use the hard-wired ones on the 1st card and the modular pair on the 2nd card. As far as which red header to plug them into, it doesn't really matter. I personally wouldn't be concerned about the 2 amp difference between /3 and /4. That card maxed out will only draw 14A.

Perhaps the extra red header is for 3 way SLI?