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z77 OC Formula issue with PCIE bandwith in SLI

post #1 of 5
Thread Starter 
I have just setup an OC formula with 2 780;s in SLI. I also have a sound card in the first PCIE 1x slot and a wifi card in the middle PCIE 1x slot between the 2 GPUS. The bottom most x16 slot is empty.

My issue is that GPUZ and all other reading software is reporting that one of my GPUs is running at 1x PCIE 3 and the other is 8x.

Can someone shed some light on this?

Here is a photo all though it may be hard to make out.

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post #2 of 5
Thread Starter 
GPUZ screenshot

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post #3 of 5
Ummm I've had a look at the manual, i have no physical experience with this board. Only things i Can suggest, is to check the card is seated properly, and check the dip switches on the board for the PCI-E slots. They're mentioned on page 48 of the manual. Other than that, they should both run at x8 according to the manual.
post #4 of 5
Thread Starter 
All slots are set to on so its not the dip switches...

I cant work it out for the life of me.

Its the main card in the primary slot that is showing its running at 1x too????
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post #5 of 5
well, i think the only way you can diagnose it, is to take all the card out the system, try each GPU in the PCI-E2 slot, check what bandwidth they get. Then try with both in the PCI-E2 and PCI-E4 slots, check again, if its at X1, swop the cards. Then if you get both running at X8, then add one of the PCI-E X1 cards at a time, checking each time you add something.

It's long and slow, I know, but it'll help you figure out what kills it down to X1......if you find one of the X1 cards is killing it, you can always try it in the last X16 slot.
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