Does PCIE passthrough work on Dell OptiPlex 5050 with Intel Core i3-6100

[Withers99]

Hello,
I want to run TrueNAS as a VM on Proxmox, I am considering using PCIE passthrough to give TrueNAS it's own network card for better performance.

The Proxmox Virtual Environment will be running on a Dell Optiplex 5050 with an Intel Core i3-6100, my question is does this PC and CPU support PCIE passthrough? I know that the Core i3-6100 supports VT-D, but I think from my research (I am new to Proxmox and TrueNAS) that I would also need IOMMU, which I am unsure if this CPU supports.

Is it possible for anybody to give me some advice on this?

 

[leesteken]

Enable VT-d in the motherboard BIOS and check your IOMMU groups: https://pve.proxmox.com/wiki/PCI_Passthrough#Verify_IOMMU_isolation
Whether passthrough actually works (when the network card is nicely isolated) can only determined by trying it.

 

[Withers99]

Enable VT-d in the motherboard BIOS and check your IOMMU groups: https://pve.proxmox.com/wiki/PCI_Passthrough#Verify_IOMMU_isolation
Whether passthrough actually works (when the network card is nicely isolated) can only determined by trying it.

Thank you, I know VT-D is enabled. I haven't purchased the NIC yet, I have found a used one on Ebay for £10 so I will go ahead and purchase it. If it doesn't work, it's not a lot of money.

 

[leesteken]

I haven't purchased the NIC yet, I have found a used one on Ebay for £10 so I will go ahead and purchase it.

You can check the IOMMU groups beforehand by using any other add-in card in the PCIe slot. Also, search the internet if anyone else got passthrough working with the NIC with TrueNAS. I don't have experience with TrueNAS but I don't expect any tangible better performance with a passthrough NIC than a separate NIC (with a standard virtual bridge).

 

[Withers99]

You can check the IOMMU groups beforehand by using any other add-in card in the PCIe slot. Also, search the internet if anyone else got passthrough working with the NIC with TrueNAS. I don't have experience with TrueNAS but I don't expect any tangible better performance with a passthrough NIC than a separate NIC (with a standard virtual bridge).

Thank you, I will do some research.

 

[DerekG]

Thank you, I know VT-D is enabled. I haven't purchased the NIC yet, I have found a used one on Ebay for £10 so I will go ahead and purchase it. If it doesn't work, it's not a lot of money.

You don't need to passthrough the NIC on Proxmox, you can setup a bridge NIC which the TrueNAS VM can use, and if required a 2nd Bridge using the onboard NIC for the other traffic.

 

[Withers99]

You don't need to passthrough the NIC on Proxmox, you can setup a bridge NIC which the TrueNAS VM can use, and if required a 2nd Bridge using the onboard NIC for the other traffic.

I had read online that using PCIE pass through rather than a bridge NIC would give better performance. Is this the case, or would I not notice the difference?

Would it be worth using two different physical NIC's, one for TrueNAS and one for other traffic, both being used as a bridge?

 

[leesteken]

I had read online that using PCIE pass through rather than a bridge NIC would give better performance. Is this the case, or would I not notice the difference?

I don't have experience with TrueNAS but I don't expect any tangible better performance with a passthrough NIC than a separate NIC (with a standard virtual bridge).

Would it be worth using two different physical NIC's, one for TrueNAS and one for other traffic

Regardless of bridge or passthrough, that really depends on whether the network bandwidth is the bottleneck. You have given no information about why you think this would be the case,

 

[Withers99]

Regardless of bridge or passthrough, that really depends on whether the network bandwidth is the bottleneck. You have given no information about why you think this would be the case,

I had read some threads online that said using bridge NIC's can have worse performance and that using PCIE pass through can help to get faster speeds. I also watched some YouTube videos on TrueNAS on Proxmox, and some of them reccomended using PCIE pass through for the NIC.

I would only be using a gigabit NIC, so I don't think the bridge would probably be a problem.

 

[leesteken]

I had read some threads online that said using bridge NIC's can have worse performance and that using PCIE pass through can help to get faster speeds. I also watched some YouTube videos on TrueNAS on Proxmox, and some of them reccomended using PCIE pass through for the NIC.

It can but it can also not give any noticeable improvement (but it does come with all the caveats of PCI(e) passthrough).

And there is no indication that the network performance is the bottleneck for your work-load, which is also not explained by you. You seem to assume or know for a fact that this approach of a separate network (with PCI(e) passthrough) will fix your performance problem, but why? Maybe if you explain how your performance problem manifests itself, people can help determine the root cause and suggest improvements (or at least experiments).

EDIT: Feel free to experiment with PCI(e) passthrough and multiple network devices, regardless. You'll learn at lot probably. And might have some fun and it does not seem to cost a lot.

EDIT2:

I would only be using a gigabit NIC, so I don't think the bridge would probably be a problem.

Sharing around 120MB/s with other network traffic might be a bottleneck if you have fast drives. Separating the storage network from the other network could very well help. But the maximum speeds are indeed easy to reach and might not need PCI(e) passthrough. Experiment and test your work-load to find the best solution for you.

 

[Withers99]

It can but it can also not give any noticeable improvement (but it does come with all the caveats of PCI(e) passthrough).

And there is no indication that the network performance is the bottleneck for your work-load, which is also not explained by you. You seem to assume or know for a fact that this approach of a separate network (with PCI(e) passthrough) will fix your performance problem, but why? Maybe if you explain how your performance problem manifests itself, people can help determine the root cause and suggest improvements (or at least experiments).

EDIT: Feel free to experiment with PCI(e) passthrough and multiple network devices, regardless. You'll learn at lot probably. And might have some fun and it does not seem to cost a lot.

EDIT2:

Sharing around 120MB/s with other network traffic might be a bottleneck if you have fast drives. Separating the storage network from the other network could very well help. But the maximum speeds are indeed easy to reach and might not need PCI(e) passthrough. Experiment and test your work-load to find the best solution for you.

Thank you, I currently don't even have Proxmox installed, I was just doing some research on it before I purchase everything I need.

I will be using a HDD for the main storage in TrueNAS, so I think that will probably be the bottle neck.

I think I will set it up and give it a try, if it feels slow on one bridge NIC then I will try it with two physical NIC's. And then if that feels slow I will try PCIE pass through.

Thank you everyone once again for all your help.