SLI Not Working

[dewman45]

I am helping a friend with SLI setup, and I am having problems I have never had before. First off, I don't want to see anything targeted towards brands of the cards, because it doesn't help.

Nvidia Control Panel won't let us enable SLI. I ask him about the cards. He says they are the same. I start thinking them over, and ask about power. This is when I learn that they have different power connectors, and are in fact not the same cards. Ok, so, the GPUs are EVGA GTX 970 SC and EVGA GTX 970 SSC. We have been trying to match the clockspeeds, and we have to get the offset correctly. We can't get them to the same clockspeed using MSI Afterburner or EVGA Precision. I need help figuring this out, since I know that these cards should work with each other. Thanks for those that can help!

[dragoon20005]

are the SLi bridge installed correctly?

 

is it the one given by the mobo?

[MegaDave91]

Try changing PCIe lane bandwidth to x8 x8 in the UEFI. 

[dragoon20005]

on second look of the GPU

 

it looks the SLi finger might be offset of each other

 

also check which slot of the PCI-E he used

 

high chance it might be in a X4 slot

[-rascal-]

on second look of the GPU

 

it looks the SLi finger might be offset of each other

 

also check which slot of the PCI-E he used

 

high chance it might be in a X4 slot

 

^This; cannot say this better myself.

 

 

Better yet, give us the make and model of the motherboard.

 

nVidia implemented a software limitation, where the PCI-Express slots must at least run at X8 speed electrically (physically). Otherwise, the drivers won't let you enable SLI.

It doesn't matter if it is PCI-Express 1.x, 2.x, or 3.0 -- they just need to be X8 minimum.

[dewman45]

Will do. I am in skype with him and another knowledgeable friend as well.

[dewman45]

Asus sabertooth 990FX r2.0

[dragoon20005]

use the first and 4th slot

[dewman45]

These solutions did not work. They are at x16 and x16. And the cards are in the right spots as the motherboard says they should be for two way SLI configuration.

[dragoon20005]

These solutions did not work. They are at x16 and x16. And the cards are in the right spots as the motherboard says they should be for two way SLI configuration.

then it could be the SLi bridge

 

are they align perfectly?

 

need a screenshot

[-rascal-]

These solutions did not work. They are at x16 and x16. And the cards are in the right spots as the motherboard says they should be for two way SLI configuration.

 

Are both cards being detected within Windows, though?

 

What does GPU-Z say?

 

ALSO, make sure all your buddy's displays / monitors are connect to the PRIMARY (top) card -- if he/she has multiple monitors.

 

then it could be the SLi bridge

 

are they align perfectly?

 

need a screenshot

 

Do you know if EVGA cards need both fingers connected for SLI?

[dragoon20005]

Are both cards being detected within Windows, though?

 

What does GPU-Z say?

 

ALSO, make sure all your buddy's displays / monitors are connect to the PRIMARY (top) card -- if he/she has multiple monitors.

 

 

Do you know if EVGA cards need both fingers connected for SLI?

nope it will work with one bridge

 

but i am concerned with the card revision

 

some recent revision have the fingers move forwards or backwards

 

so if you have a older model

 

the fingers dont align so you bridge will not work esp those rigid ones

[-rascal-]

nope it will work with one bridge

 

but i am concerned with the card revision

 

some recent revision have the fingers move forwards or backwards

 

so if you have a older model

 

the fingers dont align so you bridge will not work esp those rigid ones

 

Oh what, really?!

I thought the SLI / Crossfire connection placements are standardized  :mellow: .

This situation could get interesting...

[dewman45]

The cards are recognized by Windows, MSI Afterburner, EVGA Precision, and other programs detect them. 

[dewman45]

I just suggested to him to actually use the same EVGA cards, because that will probably solve a lot of problems and hassle right there. I initially was to believe they were the same, and ended up having to figure out the clockspeeds. The overclocking programs aren't fond of two different clocked cards and letting them match apparently, or unlink them. Nvidia says they support different cards in SLI, but I have yet to believe all configurations are covered for now. Thanks for the suggestions guys, but I think I am going to have to call it a night.

[dragoon20005]

Oh what, really?!

I thought the SLI / Crossfire connection placements are standardized  :mellow: .

This situation could get interesting...

i noticed it with the Windforce cards

[dragoon20005]

@TheSLSAMG

 

he could relate the issue with different revision

 

 

Oh what, really?!

I thought the SLI / Crossfire connection placements are standardized  :mellow: .

This situation could get interesting...

[Prolly_dyin]

Yep, It is an issue with the board revision. The ssc and Ftw+ cards are not sli compatible with the previous sc and ftw cards. I ran into this issue a while back when they were released. 

[dragoon20005]

Yep, It is an issue with the board revision. The ssc and Ftw+ cards are not sli compatible with the previous sc and ftw cards. I ran into this issue a while back when they were released. 

 

 

I just suggested to him to actually use the same EVGA cards, because that will probably solve a lot of problems and hassle right there. I initially was to believe they were the same, and ended up having to figure out the clockspeeds. The overclocking programs aren't fond of two different clocked cards and letting them match apparently, or unlink them. Nvidia says they support different cards in SLI, but I have yet to believe all configurations are covered for now. Thanks for the suggestions guys, but I think I am going to have to call it a night.

damn i was right