Play games in Windows on Linux! PCI passthrough quick guide

[GrayBoltWolf]

How fast is KVM? Host vs virtual machine performance!

So after we went through the guide on PCI passthrough, there is a question that was raised quite a bit: what exactly is the performance difference between running games in a VM vs running them natively on the host? This question has a much broader attachment to it; how well can KVM actually run a guest OS? What is the performance difference between the host and a virtual machine? I ran a slew of games and benchmarks to be able accurately represent a wide variety of performance measurements. The system used for testing is my own PC: Intel i7 4790k overclocked to 4.2 GHz 32 GB of G.Skill DDR3 RAM running on an XMP profile for a total speed of 2133 MHz EVGA GTX 980 Superclocked Gigabyte Z97MX Gaming 5 motherboard 256 GB Samsung 850 Pro M.2 SATA SSD connected directly to the motherboard’s onboard M.2 slot I used Windows 8.1 Pro as a clean install with the pre-installed metro apps removed and no internet connection, this was the same setup for the virtual machine. The host for the virtual machine was the same PC running Debian Stretch: Kernel 4.8 OVMF for UEFI support Chipset i440FX 10 GB of RAM 4 cores and 2 threads for a total of 8 threads (to mirror the host CPU) disk format was qcow2 using writeback caching disk file itself was running off of the same M.2 SSD GTX 980 passed through to the VM Emulated with KVM and all Intel virtualization technologies enabled All benchmarks and games were run with identical settings. Here is the Google Docs spreadsheet with all my data and charts. Let’s start with CPU performance. [image] CPU performance is amazingly almost the same between the host and the VM. In Geekbench the host scored 4,987 on single core and the VM scored 4,718, not bad. In both the single and multi core tests the VM’s performance was 4.5% lower than the host. [image] Cinebench yielded relatively the same result, the host scored 817, and the VM scored 775. This results in a performance difference of 5.14%. When you think about it, …

Take a look at this thread. Just use the amount of cores and threads that your host has and it will be fine.

What CPU do you have?