Please help! 3 Way SLI Not working!!

[btdvox]

Hi guys
Im having some serious issues with 3 way sli.

I have had 2 8800 ultras for awhile and just bought another one. It was tested on a different computer b4 putting into mines.

Now I have it installed and hooked up- I should let you know I meet all the specs and my PSU (enermax galaxy 1000 DXX) is definitely powerful enough.

ATM Whats odd is i boot into windows perfectly, but with the 3 way sli bridge connected, I only get the optoin to do SLI. and not 3 way sli.

I then checked GPUZ, Rivatuner etc and they all show only 2 of them.

I went into my bios and couldnt find any optoin to turn on the other pcie x 16 slot on the 780i.

Im really bogged out and cant figure this out.

I then opened my case and the fan on the new card (the one which isnt being recognized is on and running. Though If I set it to 100% on rivatuner it doesnt change at all..
I have tried 2-3 drivers now- (though I havnet done a full windows refresh- I didnt think I had too)
And still no 3 way option.

What gives?
Im pretty tech handy but this is one problem I just cant figure out!
Ive also switched around all the power cables to make sure there all running and all of them are connected.

Would the fan run if power is connected to it but even if its not seated into the PCIe Slot properly?
Thanks for any help.

 

[Nathelion]

Make sure your board isn't bowing under the weight (the entire backplate might be bending). Sometimes a lot of heavy components can do that and you can end up getting insufficient contact for the board to recognize the GPU even though the fan spins up and everything.
Is it difficult or impossible to fasten the holding screw on the front of the card?

 

[brandonb]

I know you checked out 3rd party programs but what does it say when you go into NVIDIA control panel and look at system information, does it list 3 video cards? My roommate tried to SLI in a cross fire motherboard and couldn't figure out how to get them to work (hes an idiot), but the nvidia control panel listed both cards but just no option to turn on SLI.

 

[Keysplayr]

I've asked Chris Ray to lend a hand. He's got a bunch of experience with most SLI setups. Sent him a link to this thread. Hopefully he's not on vacation or anything.

Keys

 

[quattro1]

I would uninstall your gfx drivers and reinstall them with all 3 cards installed.

Sounds like you do not have a driver installed for your third gfx card.

 

[Keysplayr]

Yes, you definitely need to reinstall the drivers.

 

[btdvox]

thanks for your replies guys, It was hard to screw the GPU in. do you think that this is the problem? What is the remedy for this? Im watercooling two of my GPUS and was going to do this one, but wanted to just let it air cool first and get tri sli working.

Im going to update my bios and then try to reseat the third card because the first two that i had are working fine. I dont see any bowing of my motherboard though, I have a Mountain Mods case and its pretty secure onto the motherboard panel.

I have uninstalled my Nvidia drivers- And installed them with 2 different versions (175.19, 169.25,)

I think i might try and do a whole new image of vista but thats a pain.

 

[btdvox]

Originally posted by: Nathelion
Make sure your board isn't bowing under the weight (the entire backplate might be bending). Sometimes a lot of heavy components can do that and you can end up getting insufficient contact for the board to recognize the GPU even though the fan spins up and everything.
Is it difficult or impossible to fasten the holding screw on the front of the card?

Yes it is a bit difficult

 

[aka1nas]

What mobo are you trying to run this on? Your sig appears out of date as that board is a P35 chipset.

You may have to set your PCI-E lane configuration a certain way depending on the chipset as some boards may not have the 3rd slot enabled in x16/x16 mode.

 

[btdvox]

Thats what I was trying to figure out! And I think this is the issue because I did a dummy test right now- I tried putting the bridge on just the 1st and middle card, And enabled sli and for some reason it said ok sli enabled, yet the two that were on sli were the 1st and 3rd card (the older cards I had before) I dont know how this was possible but im assuming if i did gaming it wouldve gave me an error. I knew this because in riva tuner the core heat was 38 and 40 (which are obv the watercooled gpus and not the aircooled one)
Secondly I then figured that If i unplugged the power with the card installed in the motherbaord I would get POST errors,
So I unplugged the power from the first card and i got a LOUD Beep stating no power to video card.
I did the same to the 3rd card- same thing no power to video card beep.
I then did this to the middle card (the new one) to see if the motherboard is recognizing it- and unplugged the power and got a BEEP!

Which means that the motherboard is recognizing the video card- and power is going to all of them.

Im assuming that I have to set something with my PCI-E lane.

I have a EVGA 780i SLI motherboard (not the FTW version)

Any Ideas? Im going to update my bios.

 

[Cuular]

From checking out the manual online for your motherboard, if all three cards are correctly inserted in the motherboard, and you've correctly connected the Tri SLI "kit", then when you go into the Nvidia control panel and tell it to go into SLI mode, it will automatically be in Tri SLI mode. The way to check this is on page 107 of your motherboard manual.

There was nothing in the BIOS setup info in the manual that says you need to set any of the PCI-e X16 slots to be anything other than that. In fact the X16 slots are hardwired to that for the best Tri SLI performance.

So I'm going to go with you may need to reseat the new card and make sure that it's not too snug.

 

[Keysplayr]

Make sure there is nothing keeping your third card from sitting fully inserted in the PCI-e slot. Like a Capacitor, or a SATA cable head.
And most importantly, check the third card, alone, in the first slot. To make sure it is a good card. Hey, you never know.

 

[btdvox]

Nope turns out my Motherboards Middle PCIe Slot is a dud. I switched out all three cards into my backup PC and thye all worked. Then I put them in the top and bottom pcie slots on the 780i and they worked! Middle ones bugged out RMA time.

 

[Keysplayr]

Hold up there a moment. You must use PCI-e slots in this order AFAIK:

Top PCI-e for single card.
Top and bottom PCI-e for SLI
and of course all 3 for TRI SLI.

You cannot use the Top and Center PCI-e slots for 2 card SLI. Nor can you use the Bottom and Center PCI-e slots for 2 car SLI. This is how it works on my 790i at least.

 

[btdvox]

^^ Yeah for sure- But what i was stating was Ive switched out all my cards in several configurations and windows wont recognize any card in the middle slot (PCI-e_16 3)

The funny thing is - windows will even recognize two cards without the SLI bridge- you can even choose to run SLI but when im assuming if you load up a game itll eventually give an error.

No matter what I tried- the middle slot never recognized any video card no matter which card I used.

I then tested all the cards on a seperate PC - in which they all worked. (one by one as it was a x38 mobo)

 

[Keysplayr]

Here is a link to the 780i manual. Go to page 104 (make sure it says 104 on the sheet itself)
and double check all you have done.

780i manual

By the way, if you have been fiddling with various settings in your BIOS, you might consider resetting BIOS to defaults.

 

[btdvox]

^^ Thanks for the help-
Ive done pretty much all this except When I ran the the Forceware Driver install- It runs installshield and only opens one install.... which was the same for SLI too.. It says in the manual itll do 3 of them...


Im assuming that this is the problem, but the fact is its still not reading it from the PCIe slot...

I did reset the CMOS jumper though and did a complete refresh of Windows Vista.

Thanks for the help though- I still cant figure it out other than the pcie slot not working

 

[cusideabelincoln]

Have you ran any games or benchmarks and confirmed any difference, or no difference, between having two cards installed vs. all three?