Linux w/ Windows VM(iommu)

Tetsujin_100 · July 13, 2018, 2:09am

Hello, this is both hardware and software related.

I wanted to ask if anyone would have experience on the performance to expect from Linux running on just a single core(without HT) and possible on one core(with HT).

My windows install is starting to act up so I was thinking about making the switch to Linux ahead of schedule since I was still saving for a Ryzen 7 or Threadripper build depending on how much functionality I want to have in a single box.

My current specs are on my profile and I was wondering if I could drive both linux(IGP) and a windows VM (iommu) with Linux only having a single core to work with to give Windows the other 3 for gaming. I was considering spending ~$80-100 on a 2600k or 2700k so I could have a bit more breathing room with hyperthreading but I though I would seek advice before spending on older hardware(though I would still have use for it later on as an HTPC build at worst)

I have been reading as I may be out of luck since the 2500k may not have VT-d. This would be yet another reason why I want to ditch windows and intel. If this is true and VT-x wouldnt work then I may be stuck dual booting, which is far from ideal.

Thanks in advance.

risk · July 13, 2018, 4:30am

Your CPU does not support vt-d.

Tetsujin_100 · July 13, 2018, 2:57pm

So there would be no workarounds available involving utilizing vt-x? I would still be able to acquire a relatively cheap non K 2500 or 2600 variant and apply this setup as those have vt-d enabled(shady business reasons?).

There is also still the question of how Linux fairs with running on only a single core with and without hyperthreading while virtualizing. Will it be stable enough to virtualize a gaming session of windows?

Thx

anon5644329 · July 13, 2018, 5:05pm

Staying on one core for linux is not a problem, be careful with the RAM you will need RAM more than a CPU. Check the guide from here.

Play games in Windows on Linux! PCI passthrough quick guide Linux

Hello all! I am Gray from GrayWolfTech. I make videos on Linux and other interesting technology. Wendell has given me permission to post my written guides here for my videos. This is great for two reasons: First it helps grow this community and second my videos reach a wider audience to share what I have learned. I look forward to posting all my guides and videos here, and I am more than happy to answer any questions about the guide you may have. – Onward! – Now it’s time for one of the coolest and more advanced capabilities of Linux. KVM, or kernel virtual machines. We are going to go through step by step, how to setup PCI pass-through to a Windows virtual machine on a Debian host to play games! Thanks to Redhat, KVM can run virtual machines with almost bare metal performance and supports a wide variety of other neat features. The one we are going to focus on in this video is of course, PCI pass-through. The process of allowing a virtual machine full access to a PCI express graphics card for gaming, CAD, or 3D rendering. With this neat capability, you can run Linux as your host OS, and then pass your GPU (or one of your GPUs if you have multiple) to a virtual machine to play games. Let’s go over the requirements for this project: First and most important, you should backup any data you have on your PC. If you know what you are doing then you will not lose anything, but accidentally selecting the wrong drive when installing can lead you to be very sad when you figure out the drive you wiped had all your really good porn on it. Second, this process will take time. For someone who is an experienced Linux user it should take about 20 minutes (not counting time to install Debian or recompile the kernel). For someone who is new it might take longer. Make sure you allow yourself an entire afternoon or a good chunk of 4-5 hours where you could potentially not have a working PC. Third, follow the instructions I lay out in the video. I will answer questions down belo…

If I am not mistaken he was using core i7 something and did 1 core and 1 thread for linux and the rest for windows VM

Tetsujin_100 · July 13, 2018, 9:24pm

If linux will smoothly(albeit probably slowly) run on a single core then I shouldn’t have a problem while im gaming if I get a cheap 2500 at least. I have a 2x8GB 1600 ram kit running in dual channel and another 2x4GB kit I can put in my rig just in case more is needed so ram shouldnt be a limiting factor.

I was hoping there was a workaround using vt-x because the loss of overclock performance wont be fun and it will still be a short while before I have enough for the new build.

Thanks.

BigBlueHouse · July 14, 2018, 3:32pm

I give all 4 cores of my 6700k to my Windows VM for gaming. And my Linux host runs fine. Obviously I don’t do anything intensive on the host while the VM is running. But for “everyday stuff” it’s no problem at all.