Looking Glass: Run a Windows VM on Linux in a Window with Native Performance

And pct can execute things inside containers so you can do everything from the host.

Thanks - that way of passing through the graphics would never have occurred.

I assume that by 'men' you mean 'cores'? If so, the host has two 6-core/12-thread CPU's (X5675@3.07GHz) and 128GB of memory, the internal array is populated with 8x146GB, the machine is hooked up to a NetApp DS4243 with 24x600GB (20 of which are in use, 4 cold spares). The machine has plenty of spare capacity, both CPU-wise as well as memory-wise. Storage is getting a bit short, eventually I'll start swapping drives in the DS4243 with higher-capacity versions. The whole contraption is housed in a sound-proofed cabinet with equipment in top, produce drying racks in the bottom. A forced draft fan all the way in the bottom of the rack draws in air through a large truck air filter in the top. This was the spare heat is used for a productive purpose instead of just wasted.

Resources are used as needed, when a container seems to be running close to capacity I add cores, memory or storage. In the current configuration I assigned 2 cores/1GB to mail, 2 cores/1GB to auth, 8 cores/8GB to build, 6 cores/16GB to (data)base, 8 cores/16GB to serve (which runs a host of web services), 6 cores/8GB to session (which runs remote desktop/single app sessions through X2go), 4 cores/1GB to panopticon (CCTV), 2 cores/1GB to p2p, 4 cores/4GB to comms and 4 cores/512MB to router. Total load on the machine is negligible, memory pressure is... absent (currently ~8GB in use, ~84GB buffer/cache, ~36GB free).

A machine like this one can be had for not that much ex-lease. As long as you get a G7 or newer power usage is acceptable, G6 and under are power hogs.

> Besides those two reasons, are there still reasons to prefer the PCI-passthrough approach?

The software approach generally has lousy performance due to the extra overhead of forwarding rendering commands between the guest and host. In addition, since this approach requires writing a completely new graphics driver for the guest, there tend to be limitations with rendering API compatibility, as well as bugs. With the hardware approach, the guest can use the GPU vendor’s normal driver.

Just yesterday I finally got to running actual tests of graphical performance between my host (Windows 7 Ultimate, NVIDIA GTX 950 - not top of the range :)) and guest (Windows 10 Pro running inside VMWare Workstation 15). Used "PerformanceTest 10" from Passmark. Host scored 6015, ran all benchmarks nicely. Guest scored 1645, only ran some benchmarks (due to lack of Dx12 and compute capabilities), and even those were penalized.

Virtualbox guest didn't participate in the contest, as I find graphical performance of VBox guests noticeably worse.

I must add though, that for desktop tasks VMWare Workstation performance is absolutely adequate, able to run double 2K monitors wonderfully. For gaming setup I'm personally planning to play with PCI-passthrough. The only problem is not to get lost in the tinkering, before playing any actual games :)

I did not try VMWare Workstation, but I did try VMWare Player and VirtualBox to see if I can get away with running Fusion 360 on a plain VM, and both had extremely horrible performance.

I remember even SketchUp wouldn't start in VirtualBox. I was able to get SketchUp running in VMWare Player, but the performance was very bad.

edit: this was also about 1.5 years ago, not sure how much improvements VMWare and VirtualBox have made in that time in terms of virtualizing GPU calls.

That is why I decided to end up setting up a VM with GPU passthru. It works extremely well for my usecase. I was able to score a cheap GPU for my Linux host (since I do not do anything graphically intensive on Linux, just need to drive 3 monitors), and was able to passthru my more expensive GPU over to the Windows VM. I would assume if you have integrated graphics on your CPU, you could use that for your host OS and get away with having only a single GPU.

I use a separate GPU for my linux host and the windows VM.

I am 99.9% sure you can not passthru a GPU to a VM that is being used by the host.

edit: I think I misunderstood your question. The GPU that gets passed thru to the VM, never gets initialized by the host system during boot. So, if you want to change which GPU you want to passthru to the VM, you will have to reboot to allow your host to use the other GPU (and not init the on you want passed thru to the VM).

I would suggest you look at a youtube video where they run thru setting this up, so you get a better idea of what this entails!

GPU passthrough with qemu/kvm works spectacularly to 3D applications, I've been using it for years to play Windows only games from my linux desktop.

This depends on the Game, but most work and VM is usually not a reason to ban players. But some AntiCheat systems like the one from Valorant try to detect VM's and refuse to run on them.

I haven’t heard of this. Why is gaming from a VM blocked?