Problems mixing GPUs on a render rig

[scarything]

Hey,

 

I've been replacing my 980 ti's in my render rig with 1080 ti's. Now i have 2x 1080 ti but the motherboard still has room/support for a third card, but i can't get the system to work properly if i add a 980 ti. 

This is not a SLI configuration or anything, i just want the cuda cores for Octane render, which usually isn't a problem.

 

I had the same issue when i tried running the system with 1x 1080 ti and 2x 980 ti, only one 980 ti would be detected. 

Is this a problem with the motherboard or is there some problem mixing Pascal + Maxwell? 

 

Now i just have a 980 ti sitting on my desk which could be of great use for it's cuda cores or just giving me display performance while the other two cards are rendering. 

 

This is my rig:

ROG X99 Gaming

5930k 

64 gb ram

2x 1080 ti 

 

Has anyone experienced something similar? I have no idea what to do. 

 

Thanks, appreciate any help i can get!

[scottyseng]

2 minutes ago, scarything said:

-snip-

That's really bizarre. Though usually you don't want to mix GPU generations like that. However, I've gotten my two 1070s and my 980 Ti in my server working fine. I sadly don't have two 980 Tis to test like you do though. I use mine for V-Ray rendering.

 

Have you tried shuffling the cards between slots? Like 1080 Ti -> top, 980 Ti -> center, and 1080 TI on bottom?

 

Though I must say, I hope you're able to keep that cool...even my 1070s were hitting 70C when next to each other. The 980 Ti I can't see being too happy since mine runs fairly hot.

[scarything]

2 minutes ago, scottyseng said:

That's really bizarre. Though usually you don't want to mix GPU generations like that. However, I've gotten my two 1070s and my 980 Ti in my server working fine. I sadly don't have two 980 Tis to test like you do though. I use mine for V-Ray rendering.

 

Have you tried shuffling the cards between slots? Like 1080 Ti -> top, 980 Ti -> center, and 1080 TI on bottom?

 

Though I must say, I hope you're able to keep that cool...even my 1070s were hitting 70C when next to each other. The 980 Ti I can't see being too happy since mine runs fairly hot.

The 1080 ti's are hybrids so they're really cool and cpu is also water cooled. I'll try shuffling around some, thanks for the advice... Ungh.. so much computing power just sitting on my desk  

[scottyseng]

Just now, scarything said:

The 1080 ti's are hybrids so they're really cool and cpu is also water cooled. I'll try shuffling around some, thanks for the advice... Ungh.. so much computing power just sitting on my desk  

Ah, I keep thinking of my server (no room for me to fit a hybrid card). Watercooled GPUs would be great for this.

 

Yeah, I also would double check the BIOS settings for PCIe lane configuration. Potentially the slot is disabled or the lanes are being used elsewhere (like NVMe drives).

 

Haha, I hope you're getting good frame times though. Even with two 1070s, rendering still is going to take me some time until I can buy another server to add more GPUs to.

 

Yeah, if that still doesn't work, I'm out of ideas on what else could be the issue. I know it's generally not recommended to mix GPU generations though. V-Ray didn't seem to care though. I'd also see if a GPU monitoring program like MSI afterburner picks up the 980 Ti.

[blu4]

Could it be a PCIe lane limitation?

[scarything]

1 minute ago, blu4 said:

Could it be a PCIe lane limitation?

I've got a 5930k so shouldn't be an issue. 

[scarything]

So when i put the 1080 ti's like this only one is detected. Wtf? I don't know much about bios, could it be some setting? Or is the mobo bad? 

[scarything]

1 hour ago, scottyseng said:

Ah, I keep thinking of my server (no room for me to fit a hybrid card). Watercooled GPUs would be great for this.

 

Yeah, I also would double check the BIOS settings for PCIe lane configuration. Potentially the slot is disabled or the lanes are being used elsewhere (like NVMe drives).

 

Haha, I hope you're getting good frame times though. Even with two 1070s, rendering still is going to take me some time until I can buy another server to add more GPUs to.

 

Yeah, if that still doesn't work, I'm out of ideas on what else could be the issue. I know it's generally not recommended to mix GPU generations though. V-Ray didn't seem to care though. I'd also see if a GPU monitoring program like MSI afterburner picks up the 980 Ti.

Alright lol. When i put the cards like this, with the 980 ti in the middle i get 1x 1080 ti detected and 1x 980 ti. But my second monitor doesnt work and i cant access Nvidia control panel because it says i dont have an nvidia card connected (when i do in fact have 3 ?).

 

I think im just going to give up and run the 2x 1080 ti.... They should be quite enough for now..

 

Also included bios with this setup which also seems completely drunk.

[scottyseng]

19 minutes ago, scarything said:

So when i put the 1080 ti's like this only one is detected. Wtf? I don't know much about bios, could it be some setting? Or is the mobo bad? 

 

You might try seeing if there's a bios update for your motherboard.

 

Also you might try putting the middle GPU in the 4th slot (x16_2). It says right there in the BIOS you need to use the first, 4th, and last slot for 3 GPUs. Or the first and 4th slot for two GPUs.

[scarything]

7 minutes ago, scottyseng said:

You might try seeing if there's a bios update for your motherboard.

 

Also you might try putting the middle GPU in the 4th slot (x16_2). It says right there in the BIOS you need to use the first, 4th, and last slot for 3 GPUs. Or the first and 4th slot for two GPUs.

I just got it working! I checked my device manager and there was an unknown VGA device that i installed and now i got the 2x 1080 1x 980, running Octane bench now to see if they all work properly. 

 

i think the way they're seated now is the only way it fits.. but maybe im being stupid. I'll remove the 980 ti again.

 

Thanks for the help!