IOMMU/PCI Passthrough to Windows with KVM

[blackice8r]

I've looked around but couldn't see a thread on this.

a bit about myself:
I'm a linux noob but I would love to be able to run linux and power windows only when I want to play games.
I have a basic understanding of linux , have my own little ubuntu server (on an Intel NUC) for files (Drobo attached via USB) and Plex.
I manged to stick to linux on my desktop for about two months until I started gaming again..
I plan to get a new Ryzen system (my i5 3570k doesn't support IOMMU so I can't test KVM atm.)

Before I buy stuff I started doing some research and the results seem to vary.
Some claim this is working fine , with 2-5%max performance loss (Cpu -GPU) : https://forum.level1techs.com/t/play-games-in-windows-on-linux-pci-passthrough-quick-guide/108981
While other sources show mixed results: https://level1techs.com/video/ryzen-iommu-pcie-passthrough-works

The way I understand it, the problem seems to be the support on the motherboard. Not all manufacturers offer it, while others promise it in future BIOS updates.

I was wondering if anyone has a working KVM for gaming, any recommendations on a safe mobo to buy and advice on the performance loss ? (is it indeed just 2-5% ?)

 

[blackice8r]

This may help, Wendell is one of the few YT tech people who actually know what they are doing.

I know Gigabyte have sorted theirs (K5/7)

Bear in mind, you will need a AMD GPU to pass through, unless you have a NV Quodro based card

Manny thanks for the replies guys!

I've seen that vid but never watched it fully, I've taken the time to do that today.
I understand more but the issues I feared remain:
- which motherboard provides the support ? The two he suggests are double the price of what I had in mind, I was going to get a B350 or a cheaper X370
- he claims gaming works, cool but whats the real performance loss? I see frame drops on the game tests he has running while recording.
Getting some games to work under linux is one thing, getting performance similar to Windows for AAA titles is a different thing.
- one thing I didn't think before this vid was - potentially - the need for a second Ethernet port on top of the two graphics (I was hoping to use an on board graphics and my gtx970)

Good to know there are workarounds to get Nvidia cards working.I have a gtx970 and I was hoping Vega would be the next upgrade but the news so far aren't that promising.
I don't know a great deal about unRAID but it looks like traditional virtualization, I'd prefer passthrough because in theory there is less performance loss.
The point with building a ryzen setup is to build a cost efficient pc (£200 mobo would defeat the point) that would compete on performance with an Intel setup. I plan to overclock at ~4ghz.

Anyone else has a working set-up?

I'm not in a huge rush with this just doing the research and find the potential very interesting