3GPU Crashing system completely

[JoeWilson476]

Hi,

I have recently built a small mining rig and I am having troubles getting the 3rd card to work at all. I can run any 2 out of 3 cards. But whenever I try to run all 3. The system bricks. Fans spin but nothing happens. I am using a B450 F Rog STRIX. 8GB of ram and risers. The cards are an RTX 3090. RTX 3080 which I can run fine. But when I try to use a 5700 XT the system blacks out and I get no video. I have tried everything that I can think of. Used different slots. Played with the BIOS. Not having any luck at all. I’m using windows 10. Any help would be very much appreciated as I am currently stuck.
Thanks

 

[Zach_01]

Have you enable "Above 4G Decoding" in BIOS?

So, when you are using only one 30series card and the 5700XT, does it works?

And what are the rest details of the system?
PSU?

 

[JoeWilson476]

Have you enable "Above 4G Decoding" in BIOS?

So, when you are using only one 30series card and the 5700XT, does it works?

And what are the rest details of the system?
PSU?

Yeah it has worked with one 30series and a 5700xt but never with more than the 2 cards. 4G is enabled. and the PSU is a Corsair HX1000. I am using The first 3 slots but i have tried a lot of variations and none have worked so far.

Thanks for your time

 

[Zach_01]

Sorry for didnt ask this earlier, but did you configure all GPUs to draw less power than they do for gaming? Like underclock and under voltage their GPU. VRAM should be on max.
All these 3 GPUs at their nominal power draw can reach or exceed 900W and if you add the rest of the system then you drive this PSU to its limits.

 

[Why_Me]

Hi,

I have recently built a small mining rig and I am having troubles getting the 3rd card to work at all. I can run any 2 out of 3 cards. But whenever I try to run all 3. The system bricks. Fans spin but nothing happens. I am using a B450 F Rog STRIX. 8GB of ram and risers. The cards are an RTX 3090. RTX 3080 which I can run fine. But when I try to use a 5700 XT the system blacks out and I get no video. I have tried everything that I can think of. Used different slots. Played with the BIOS. Not having any luck at all. I’m using windows 10. Any help would be very much appreciated as I am currently stuck.
Thanks

Off topic but how did you manage to get your hands on an RTX 3090 and 3080.

 

[JoeWilson476]

Sorry for didnt ask this earlier, but did you configure all GPUs to draw less power than they do for gaming? Like underclock and under voltage their GPU. VRAM should be on max.
All these 3 GPUs at their nominal power draw can reach or exceed 900W and if you add the rest of the system then you drive this PSU to its limits.

Hi, I figured i might need another PSU but yeah youre right. I did undervolt all of them. However whenever i touch the settings on the 3080 it just straight up crashes and i have to restart and quickly reset the card to normal settings otherwise it crashes again. I've not found a fix to this either. I will be buying another PSU as i have just gotten another 5700XT from Currys. So this would be 4 cards now which defo needs a second PSU. I will get one ordered and then @ you again to tell you my findings.
Thanks

Off topic but how did you manage to get your hands on an RTX 3090 and 3080.

Hi mate, I got the 3090 from currys, its the PNY XLR8 so the RRP was £1730 and i got the 3080 off a local computer shop for £1000. I know its over RRP but thats the times and its certainly worth it considering the cards will pay for themselves anyways