Question Problems with Multi GPU setup ?

[CosmicEgg_]

Hi guys,

I'm currently trying to setup a PC with both a GTX 1080 and an RTX 3090 Ti but i'm struggling to get it to work.

I tried many things but the current result is the 1080 booting with a code error 43 in device manager but work after a disabled enable and the 3090 Ti gets a code 45 and doesn't work at all.
Best I got was the 1080 working perfectly and the 3090 Ti showing up with no error but displaying nothing.

I can provide more informations on what I already tried and the result, I just don't that here it will be insanely long but I tried differents drivers, Windows reinstall, checked PSU, monitor and motherboard connections, etc.

Does someone have any ideas ?

 

[COLGeek]

What are the complete specs for this system? We need to know the make and model of each installed component. Details matter.

 

[CosmicEgg_]

Yeah sorry I forgot these, my bad.

-ryzen 7 5800x
-asus x570 e gaming
-32go 4x8 ddr4 3600mhz
-asus 1080 o8g
-nvidia 3090ti fe
-corsair 850w (main psu)
-generic 650w (psu for the 1080 only)
-2 m.2 nvme
-win 10 (up to date)

 

[QyInvoLing]

It's difficult to use two different gen cards made by the same manufacturer. Why do you do that?

 

[CosmicEgg_]

It's difficult to use two different gen cards made by the same manufacturer. Why do you do that?

Well because I have multiples monitors and I have a useless 1080 otherwise. Why would it be hard ? Some people seem to just plug the cards and it's working

 

[COLGeek]

How are you sending the power on signal to the second PSU?

Well because I have multiples monitors and I have a useless 1080 otherwise. Why would it be hard ? Some people seem to just plug the cards and it's working

Your newer GPU can easily handle more than one monitor. Sell the older one, or keep as a backup. You really don't need two GPUs.