Sparkles Posted February 8, 2020 Share Posted February 8, 2020 (edited) Specs: Cpu: i7 3930K Motherboard: Asus P9X79 Pro Ram: 32 GB DDR3 GPU: AMD 4650 I'm new to unRaid and experiencing issues trying to get the GPU pass through working on my setup. On the info screen it shows IOMMU is disabled but have been unable to get it enabled and to show GPU as an option when setting up a VM. I have done a bunch of research and have confirmed that the CPU and Motherboard are compatible with IOMMU and vt-d. I have tried the following: Updated BIOS to the latest version Enabled every CPU option that i could find (none of which explicitly say vt-d or iommu) The closest was one that references Vanderbelt Technology Checked System Agent Configuration as most other posts and guides for Asus boards show, but the only options there is to change the generation of the PCIe slots Set PCIe ACS override to Downstream i unRAID Added intel_iommu = on to the syslinux.cfg and verified it's loading with this when launching unRAID on boot BOOT_IMAGE=/bzimage intel_iommu=on vfio_iommu_type1.allow_unsafe_interrupts=1 pcie_acs_override=downstream initrd=/bzroot Tried iommu=pt in place of intel_iommu = on BOOT_IMAGE=/bzimage iommu=pt vfio_iommu_type1.allow_unsafe_interrupts=1 pcie_acs_override=downstream initrd=/bzroot From what i can find these Motherboards do not have a northbridge, so there is no settings for that. Before I try rolling back my BIOS is there anything else i should look for or try? SOLVED: after some more digging there are multiple versions of the 3930k and I have the older version which doesn't work properly with vt-d. Thanks for the help everyone. EDIT: Dropped in a i7 3820 CPU and works like a charm. VT-D is showing in the BIOS, and IOMMU is enabled and showed properly in unRaid. i hope this helps another poor soul like me at some point tower-diagnostics-20200208-1435.zip Edited February 13, 2020 by Sparkles Quote Link to comment
JorgeB Posted February 9, 2020 Share Posted February 9, 2020 8 hours ago, Sparkles said: none of which explicitly say vt-d There should be one explicitly mentioning vt-d, most times it's not on the CPU section. Quote Link to comment
bastl Posted February 9, 2020 Share Posted February 9, 2020 (edited) @Sparkles The BIOS of 4xxx gen AMD GPU's don't have UEFI support and therefore you won't be able to pass them trough to a VM. I don't think there are models sold with UEFI support. Below just an example from TechPowerUp Edited February 9, 2020 by bastl Quote Link to comment
itimpi Posted February 9, 2020 Share Posted February 9, 2020 Getting IOMMU enabled is purely a hardware/BIOS issue and not something you can change by tweaking Unraid settings. According to the User Manual for your motherboard this you need Advanced => CPU Configuration => SVM setting enabled Advanced => Northbridge => IOMMU enabled Until the BIOS reports that IOMMU is enabled no sort of hardware pass through to a VM is possible. Quote Link to comment
Sparkles Posted February 10, 2020 Author Share Posted February 10, 2020 17 hours ago, johnnie.black said: There should be one explicitly mentioning vt-d, most times it's not on the CPU section. There is none, I've been through all the options in the BIOS and don't see it 15 hours ago, bastl said: @Sparkles The BIOS of 4xxx gen AMD GPU's don't have UEFI support and therefore you won't be able to pass them trough to a VM. I don't think there are models sold with UEFI support. Below just an example from TechPowerUp I did not know this. I however did put in a 750ti and am a still having the same issue. I even tried both cards as per another post i've seen since my Motherboard doesn't have onboard video 15 hours ago, itimpi said: Getting IOMMU enabled is purely a hardware/BIOS issue and not something you can change by tweaking Unraid settings. According to the User Manual for your motherboard this you need Advanced => CPU Configuration => SVM setting enabled Advanced => Northbridge => IOMMU enabled Until the BIOS reports that IOMMU is enabled no sort of hardware pass through to a VM is possible. There is no northbridge on this motherboard. and don't see anything for SVM From intel ark it says "This product includes VT-d support only on the C2 stepping" I noticed on my Bios it says Southbridge stepping is at C0 stepping, now to find out how to change this option. This is the BIOS settings : https://imgur.com/a/Ib0oY90 Quote Link to comment
itimpi Posted February 10, 2020 Share Posted February 10, 2020 43 minutes ago, Sparkles said: There is none, I've been through all the options in the BIOS and don't see it I did not know this. I however did put in a 750ti and am a still having the same issue. I even tried both cards as per another post i've seen since my Motherboard doesn't have onboard video There is no northbridge on this motherboard. and don't see anything for SVM From intel ark it says "This product includes VT-d support only on the C2 stepping" I noticed on my Bios it says Southbridge stepping is at C0 stepping, now to find out how to change this option. This is the BIOS settings : https://imgur.com/a/Ib0oY90 Sorry - I was looking at the wrong User Manual Are you sure that motherboard supports IOMMU? When I looked at the correct User Manual I could not see any reference to such support. Quote Link to comment
Sparkles Posted February 10, 2020 Author Share Posted February 10, 2020 @itimpi The manual doesn't say anything about iommu but the bios update 0906 says it enabled "Enable VT-d support for VT-d enabled processor." now my fear is that the motherboard doesn't support the C2 stepping that the CPU needs. ref: https://www.asus.com/ca-en/Motherboards/P9X79_PRO/HelpDesk_BIOS/ Quote Link to comment
Mark McDonald Posted February 13, 2021 Share Posted February 13, 2021 I have the same motherboard - any solution to this? Quote Link to comment
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