SLI cannot be enabled with 980GTX of different brands?

[migs97a]

Hi.
I can't get the option of SLI to be enabled for my system. I have two 980GTX (Zotac and MSI).
I have tried a fresh install of the drivers, os, swapping the cards. It always says SLI Disabled.
There is no option to enable it, the nvidia control panel tells me to install compatible cards and bridge. Windows and all hardware monitoring programs detect both cards as 980gtx 1 or 2 and I have tested that both work in a single card setup.

My system:
I7-5820k
Gigabyte X99 G1 MB
16gb DDR4 Ripjaw
Zotac 980GTX AMP Extreme 4gb (In PCI Slot 1)
MSI 980 GTX Gaming 4gb (In PCI Slot 2)
Corsair 1,000 PSU

After checking the forums I saw problems with 970s of different brands so I installed the Different SLI 1.2 workaround. Now SLI works, but on the nvidia control panel its says, for best performance install a sli bridge.

Anyone else having a problem with enabling SLI on differerent brands of the same card type? e.g. both 980gtx.

I thought SLI can work on different brands just as long as its the same type?

Is there a performance hit with using DifferenSli?

Thanks.

 

[Vayra86]

Are you using the right PCI slots? *edit: the spec page says slot PCIE1 and 2.

 

[newtekie1]

Now SLI works, but on the nvidia control panel its says, for best performance install a sli bridge.

Something is wrong with your SLI bridge. It either isn't connected properly, or the bridge is bad.

It looks like your motherboard comes with both a SLI and crossfire bridge. Make sure you are using the SLI bridge and not the crossfire bridge.

 

[migs97a]

Something is wrong with your SLI bridge. It either isn't connected properly, or the bridge is bad.

It looks like your motherboard comes with both a SLI and crossfire bridge. Make sure you are using the SLI bridge and not the crossfire bridge.

SLI only works if I install DifferentSLIAuto. Once I uninstall that or don't use it, SLI stops working at all. If I use it, it says for best performance install a sli bridge. I'm not sure how it works, if it bypasses the sli bridge.

I used the Bridge labelled NVIDIA SLI which came with my motherboard, I also bought 4 other NVIDIA bridges just to test, still no go. Is there a particular way we are supposed to plug it? Like only the left or right plugs if its two way sli?

Also something I noticed in Device Manager of Windows, The first GTX 980 Location is Indicated in PCI Slot 4(PCI bus 6, device 0, function 0) and the second GTX 980 Location is indicated in PCI Slot 6 (PCI Bus 3, device 0, function 0). Im sure I did not put it in those slots since Slot no. 4 is the 2nd long pci physical slot on the motherboard and its empty and Slot no 6 is the short looking slot and I didn't use that.

 

[Vayra86]

I really do think you need to refer to your MB manual and see what PCI slots to use for a dual card setup. It differs per mobo. On the mobo itself it will say by each slot which number it has, usually starting at 0. There is a similar thread on here where this has resolved the OP's problem. (This is because SLI requires a x8 PCI slot minimum or it won't work, and not all PCI lanes will have x8 base config even if they all look like a full length slot)

*This may not be the same number as the one you find when you look at PCI slots in Windows device manager though - that number is less relevant, it is a device number that Windows puts on it and has nothing to do with the physical slot location.

DifferentSLIAuto may actually screw up more than it will solve - the GPU on your cards is the same one, so by default SLI should be flawless. Brand generally doesn't matter. DifferentSLIAuto may tell you it works, but what matters is real performance gains, not what software tells you.

 

[newtekie1]

Can you post GPU-Z screenshots from each card?

 

[Caring1]

If they are in the correct slots, then you may have to down clock the card with the highest base clock to match the other card.
The slots are marked so that slot one is nearest the CPU, slot 2 is the 3rd x16 slot down, in other words leave the one long slot empty between the cards.

 

[OneMoar]

If they are in the correct slots, then you may have to down clock the card with the highest base clock to match the other card.

what .... no ... it doesn't work like that

 

[Caring1]

what .... no ... it doesn't work like that

Thanks for that insightful look into how it does work ....

 

[OneMoar]

Thanks for that insightful look into how it does work ....

GOOGLE IT SON

 

[qubit]

@migs97a I'll bet this is really frustrating for you.

Although rare, it's just possible that one of your cards has a hardware fault with the SLI connector so the physical connection isn't being made. That would be consistent with the driver recommending the bridge when you use that SLI patch software. If possible, grab another 980 and try it with each of those cards in turn. If it fails with one of them, there's your answer.

Finally, double check that your motherboard is in SLI mode and not CrossFire mode. Best do this bit first!

 

[migs97a]

@migs97a I'll bet this is really frustrating for you.

Although rare, it's just possible that one of your cards has a hardware fault with the SLI connector so the physical connection isn't being made. That would be consistent with the driver recommending the bridge when you use that SLI patch software. If possible, grab another 980 and try it with each of those cards in turn. If it fails with one of them, there's your answer.

Finally, double check that your motherboard is in SLI mode and not CrossFire mode. Best do this bit first!

Argh. I don't want to buy another card. lol. And the space between the Zotac and MSI is probably too small to put another video card if I was going to 3 way sli. The Zotac card in the first slot is huge. I had to get the MSI because the Zotac were out of stock already with no timeline on when it would be in stock again.

I read on the Geforce forums that some people were having problems getting 970s (so maybe 980s also) from different manufacturers to SLI, I am wondering if its just a driver problem since the cards are relatively new and that DifferentSLI hack seems to make it work with just changing a driver system file - nvlddmkm.sys.

 

[migs97a]

Here is a screenshot of my Cards with GPUZ

 

[migs97a]

Are you using the right PCI slots? *edit: the spec page says slot PCIE1 and 2.

Hi, sorry didn't see your message, yes, I put the Zotac in PCIE 1 and the MSI in PCIE 2 as indicated in the manual. Physically on the board its the 1st and 3rd long slots

 

[Caring1]

Argh. I don't want to buy another card. lol. And the space between the Zotac and MSI is probably too small to put another video card if I was going to 3 way sli. The Zotac card in the first slot is huge.

Hopefully this pic helps, the third card doesn't sit in the middle.

 

[qubit]

Argh. I don't want to buy another card. lol. And the space between the Zotac and MSI is probably too small to put another video card if I was going to 3 way sli. The Zotac card in the first slot is huge. I had to get the MSI because the Zotac were out of stock already with no timeline on when it would be in stock again.

I read on the Geforce forums that some people were having problems getting 970s (so maybe 980s also) from different manufacturers to SLI, I am wondering if its just a driver problem since the cards are relatively new and that DifferentSLI hack seems to make it work with just changing a driver system file - nvlddmkm.sys.

No, I didn't mean for you to buy another card necessarily. Do you have a friend with one, perhaps? Yes, while it could be a software issue, cards from all vendors are supposed to be compatible with each other in SLI. It might be worth checking the Zotac and MSI websites for vbios updates which might resolve this issue.

You might not know someone with such a card, of course. Now, I don't know where you live, but if you live in the USA or UK, you could buy another 980 from Amazon use it for testing and then return it. They have a very generous one month no questions asked return policy, so doing this carries no risk for you.

Finally, I wasn't suggesting 3 card SLI. Just install the new card with one of the old ones and see how it works, then repeat it with the other old card. If it fails with one card, then there's your answer. RMA that one.

 

[matreks]

I had the same problem with my 970's. I have a EVGA ACX and a Windforcex3 and the only way to get them to work in sli was to use differentsli. I compared benchmark scores to people with the same setup just to be sure it was working as it should.

 

[migs97a]

I was able to test the both cards with a matching card. SLI works on both cards with the same manufacturer. At least I know the cards are not defective. Hopefully this gets sorted out in a driver update. Did any of the earlier series of gpus have this problem before?

 

[Caring1]

Pretty sure it didn't matter who made the card as long as the amount of Vram and the clock settings were the same, and they were the same series.
But google or another posters input might help.

 

[qubit]

I was able to test the both cards with a matching card. SLI works on both cards with the same manufacturer. At least I know the cards are not defective. Hopefully this gets sorted out in a driver update. Did any of the earlier series of gpus have this problem before?

Sounds like this problem is somewhere between the driver and the bios from the manufacturer and is totally unacceptable in my opinion, especially given the significant amount of money that two of these cards cost.

There was a time when cards had to be identical models from the same manufacturer, but we're probably going back a decade or so, therefore there's no good reason why this should be an issue now. If you want to email NVIDIA, Asus and MSI about this problem it might be a good idea that they know. They probably already do, but every complaint reinforces the urgency of the problem, even if you don't get a reply.

A black eye to NVIDIA on this one as it's up to them to ensure the compatibility standard is adhered to.

btw, I've just ordered a second MSI GTX 780 Ti Gaming graphics card. I made the mistake of having a casual browse at Scan and saw it there for £330 - absolutely irresistible! Just looked again and it's already out of stock and on pre-order. With such a hot buy I'm not surprised.

 

[migs97a]

I already sent a feedback email to NVIDIA regarding this. After doing a search on this topic, I saw a lot of threads regarding this problem, though mostly on the 970s. But I guess it could also affect the 980s since its in the same series?

https://forums.geforce.com/default/topic/781585/sli/can-t-enable-sli-with-2x-gtx-970-updated-/

this guy couldn't even get his 970s to SLI and they were both from EVGA, but different specs and a tech support guy commented saying that some 970s will not SLI with each depending on the model of the 970. I also found a link to their Official Page re. this issue
https://www.evga.com/support/faq/afmviewfaq.aspx?faqid=59534
http://forums.evga.com/having-trouble-with-SLI-970s-one-reference-one-not-m2242757.aspx

https://forums.geforce.com/default/topic/782877/980-sli-will-not-work-says-bridge-is-missing-/

They should update SLI FAQ on the Nvidia website to state that this is no longer possible or guaranteed:

Can I mix and match graphics cards from different manufacturers?
Using 180 or later graphics drivers, NVIDIA graphics cards from different manufacturers can be used together in an SLI configuration. For example, a GeForce XXXGT from manufacturer ABC can be matched with a GeForce XXXGT from manufacturer XYZ.
Can I mix and match graphics cards if one of them is overclocked by the manufacturer?
Yes. A GeForce XXXX GTX that is overclocked can be mixed with a standard clocked GeForce XXXX GTX.

 

[qubit]

Well, technically you still can mix different brands of card together therefore technically a warning isn't required, so this sounds like piss-poor quality control on NVIDIA's part. NVIDIA really needs to be kicked up the ass with competition - that would focus their mind on this problem.

With my new card, of course I won't see this problem since it's an identical model to the one I already have. But will a vbios revision cause problems...

 

[migs97a]

LOL, maybe just a warning regarding the 900 series. I hope they can fix it through a driver update, but some of those posts are from October and its still not fixed

 

[migs97a]

http://forums.evga.com/Unable-to-Configure-SLI-in-Nnidia-Control-Panel-m2209638-p2.aspx

Some EVGA Tech stated that the Device IDs of the Video Cards should be the same for SLI to work with the Nvidia Drivers (for the 780). I checked my two video cards and they have different hardware ids so I guess maybe that's the problem.


Dear Valued Customers,

I can confirm that we have looked further into this with our product management team and it is confirmed that the cards must be of the same device ID to ensure that SLI is working through the Nvidia drivers without modification. We are very sorry for any confusion that may have been caused and if anyone needs help with their SLI with the GTX 780 6GB model cards then please email me at chrisb@evga.com or call our 24 hour support at 1-888-881-3842 option 1 and we will work with you.
post edited by EVGATech_ChrisB - Thursday, October 02, 2014 9:12 AM

 

[qubit]

"Dear Valued Customers". Classic.

I wonder why the device ID is different for the same level of card? Even if you compare a tricked out version with things such a fancy cooler, twice the RAM, a fat factory overclock and a dual BIOS, compared to a reference version it should have the same ID.

NVIDIA still doesn't get off the hook in my book, as they're supposed to regulate this sort of thing.