Hi all

 

I am trying to get two gpus recognised by unraid and I am wondering if its the mobo at issue. i have tried gtx 970, amd 480, amd 7870, amd 6450 passive. I cant seem to get two recognised at once, even if i choose the acs override. 

For example if i put 970 in the first pcie gpu slot and then the 6450. Only the 970 is seen by unraid. Yesterday i tried the 480 in the first gpu slot then the 7870 - this worked to start with now only the 480 is visible. Its doing my head in

 

I have a 4790k cpu. Bios is latest 3003.

 

Any suggestions greatly appreciated. Do i need a asrock mobo or are iommu groups dictated by the cpu?

 

Edited October 31, 20178 yr by Guest

Is the board thinking that you're trying to SLI the cards or something odd like that?

No i dont think so, im not using an sli bridge. Not that sli is supported by unraid anyway

I'm not familiar with SLI, but there's nothing in the BIOS settings that configures the PCI slots?

 

Looking at the motherboard manual, the 1st PCI-E 3.0 slot is shared with the bottom PCI slot, and the 2nd GPU slot is shared with the top 1x slot. Are you running any other cards that may be sharing IRQs?

holy crap i have my usb card in the top 1x slot. Do you think thats why the 2nd gpu slot isnt appearing to unraid Allan?

Possibly, check out the manual page 38/39 for the table on what slots have shared resources:

 

http://dlcdnet.asus.com/pub/ASUS/mb/LGA1150/MAXIMUS-VII-RANGER/E9798_maximus_vii_ranger_ug_v2_WEB.pdf?_ga=2.130645514.421542517.1509441315-176744399.1509441315

 

Ok so if I read this right, if I put the usb card in the third slot then that shouldnt interfere with either of the gpu slots? Thanks for your help on this Allan

Yes, from the tables it appears that slot isn't shared.

After a lot of testing, the fault lies with the 2nd gpu slot. Its faulty - 2nd gpu doesnt appear in the bios. Time for a hardware refresh huzzah!