6 ms·

Just a reminder that enabling Hyper-V (needed for WSL2) will make your computer boot your current Windows install inside a VM too. This might makes a slight per

Just a reminder that enabling Hyper-V (needed for WSL2) will make your computer boot your current Windows install inside a VM too. This might makes a slight performance impact. And you might also encounter issues with Type 2 virtualization software such as VirtualBox or VMWare Workstation. (I will still stick to WSL 1 because of that).

jfkebwjsbx 6y ago
This is a very important detail, yeah. For ML, 3D, games and what not is probably better to keep Linux in another kind of VM.
exacube 6y ago
that seems odd; what is the performance impact of turning on Hyper-V for the root/host windows instance?
- zlynx 6y ago
  Basically no impact. At least for me. Some people seem to get terrible performance, but I don't know why. Their drivers? Or is it trying to run without Virtualization enabled in BIOS? AMD-V, VT-x, VT-d? I don't consider it odd. It is the way a Type 1 hypervisor works. Windows puts in some effort to hide most of that from the user.
- alibert 6y ago
  Unfortunately I have no number to give you. I did a search on the subject a while ago and all that I could find is numerous post on multiple forums with people indicating slowness, lower fps in games, shuttering. Weirdly, this is something that could be tested pretty easily with a benchmark. In my understanding on how a Hypervisor works, the only thing that I'm almost confident to say is that there is an impact but it's probably not noticeable or highly related to your workload (maybe on I/O?). People will probably not care about that impact in fact (considering that Hyper-V is enabled by default and there are multiple security features of Windows now relying on Hyper-V).
e12e 6y ago
Any benchmarks on this? For laptops I'd be mostly interested in seeing battery tests - otherwise I guess a compiler benchmark, and some gaming numbers. I'd be a little surprised if it really is measurable - just win10 with/without hyper-v? I seem to recall xen (which should be comparable) having a pretty low impact?
runjake 6y ago
You may be right but: 1.) The Hyper-V component isn't installed on my Windows 20H1 install. WSL 2 may use Hyper-V technology, but the full thing does not appear to be installed. 2.) So far, VirtualBox is working just fine. I haven't noticed any issues yet while using several virtual machines. Nothing seems amiss at all.
- alibert 6y ago
  Is "Hyper-V" or "Windows Hypervisor Platform" enabled in Windows Features screen?
- temac 6y ago
  The Hyper-V hypervisor is obviously running. I don't remember the corresponding name in the optional components. The complete Hyper-V suit you use to manually create and run VM does not need to be installed by default, but that's irrelevant. Windows provides more and more features that relies on the hypervisor, e.g. Windows Sandbox, Edge Protected Mode, Credential Guard, etc. Those features (and WSL2) are not available when you are not running under the hypervisor. MS also provides an API so that third party VM tools can run, and Virtual Box can use it, but still recently it had tons of issues. Maybe the situation is somehow better now, I don't know. I don't think this is an option with VMWare though.
  - alibert 6y ago
    Indeed, until very recently, Virtual Box could not be run with Hyper-V enabled. One the recent release, fixed that but the price was some performance optimization was disabled. So it's not optimal [1]. VMWare has a tech preview of the next version of Workstation which should work with the new Windows 2004 [2] [1] https://forums.virtualbox.org/viewtopic.php?p=470529#p470529 https://forums.virtualbox.org/viewtopic.php?p=470529#p470529 [2] https://blogs.vmware.com/workstation/2020/01/vmware-workstation-tech-preview-20h1.html https://blogs.vmware.com/workstation/2020/01/vmware-workstat...
happypants23 6y ago
Just a reminder that enabling Hyper-V (needed for WSL2) will make your computer boot your current Windows install inside a VM too. This might makes a slight performance impact. That doesn't sound right. Hyper-V is a Type-1 hypervisor, so by definition the Windows installation would not be running in its own VM (for some definition of VM). And its pretty much exactly the same for Qemu/KVM on Linux, where Intel VT-x or AMD SVM hardware extensions are used to implement Type-1 virtualisation.
- deleted 6y ago
  [deleted]
- alibert 6y ago
  Unless I'm terribly wrong, when Hyper-V is enabled, it converts the current host Windows to a "Parent partition". This is what it's described here: https://superuser.com/questions/836116/hyper-v-appears-to-runs-on-top-of-the-host-os-so-why-is-it-considered-a-native https://superuser.com/questions/836116/hyper-v-appears-to-ru...
megavolcano 6y ago
The thing about Type 2 virtualization not working is true, but if you hyper-v enabled you already have type-1 virtualization so type 2 is kinda irrelevant. I've been using Hyper-V for about 5 years and never noticed any performance impact worth mentioning. Type 1 hypervisor VMs are still technically running on the metal.
galkk 6y ago
VMWare has beta Workstation that integrates with Hyper-V.

jfkebwjsbx 6y ago

This is a very important detail, yeah. For ML, 3D, games and what not is probably better to keep Linux in another kind of VM.

exacube 6y ago

that seems odd; what is the performance impact of turning on Hyper-V for the root/host windows instance?

zlynx 6y ago
Basically no impact. At least for me. Some people seem to get terrible performance, but I don't know why. Their drivers? Or is it trying to run without Virtualization enabled in BIOS? AMD-V, VT-x, VT-d? I don't consider it odd. It is the way a Type 1 hypervisor works. Windows puts in some effort to hide most of that from the user.
alibert 6y ago
Unfortunately I have no number to give you. I did a search on the subject a while ago and all that I could find is numerous post on multiple forums with people indicating slowness, lower fps in games, shuttering. Weirdly, this is something that could be tested pretty easily with a benchmark. In my understanding on how a Hypervisor works, the only thing that I'm almost confident to say is that there is an impact but it's probably not noticeable or highly related to your workload (maybe on I/O?). People will probably not care about that impact in fact (considering that Hyper-V is enabled by default and there are multiple security features of Windows now relying on Hyper-V).

e12e 6y ago

Any benchmarks on this? For laptops I'd be mostly interested in seeing battery tests - otherwise I guess a compiler benchmark, and some gaming numbers. I'd be a little surprised if it really is measurable - just win10 with/without hyper-v? I seem to recall xen (which should be comparable) having a pretty low impact?

runjake 6y ago

You may be right but: 1.) The Hyper-V component isn't installed on my Windows 20H1 install. WSL 2 may use Hyper-V technology, but the full thing does not appear to be installed. 2.) So far, VirtualBox is working just fine. I haven't noticed any issues yet while using several virtual machines. Nothing seems amiss at all.

alibert 6y ago
Is "Hyper-V" or "Windows Hypervisor Platform" enabled in Windows Features screen?
temac 6y ago
The Hyper-V hypervisor is obviously running. I don't remember the corresponding name in the optional components. The complete Hyper-V suit you use to manually create and run VM does not need to be installed by default, but that's irrelevant. Windows provides more and more features that relies on the hypervisor, e.g. Windows Sandbox, Edge Protected Mode, Credential Guard, etc. Those features (and WSL2) are not available when you are not running under the hypervisor. MS also provides an API so that third party VM tools can run, and Virtual Box can use it, but still recently it had tons of issues. Maybe the situation is somehow better now, I don't know. I don't think this is an option with VMWare though.
- alibert 6y ago
  Indeed, until very recently, Virtual Box could not be run with Hyper-V enabled. One the recent release, fixed that but the price was some performance optimization was disabled. So it's not optimal [1]. VMWare has a tech preview of the next version of Workstation which should work with the new Windows 2004 [2] [1] https://forums.virtualbox.org/viewtopic.php?p=470529#p470529 https://forums.virtualbox.org/viewtopic.php?p=470529#p470529 [2] https://blogs.vmware.com/workstation/2020/01/vmware-workstation-tech-preview-20h1.html https://blogs.vmware.com/workstation/2020/01/vmware-workstat...

happypants23 6y ago

Just a reminder that enabling Hyper-V (needed for WSL2) will make your computer boot your current Windows install inside a VM too. This might makes a slight performance impact. That doesn't sound right. Hyper-V is a Type-1 hypervisor, so by definition the Windows installation would not be running in its own VM (for some definition of VM). And its pretty much exactly the same for Qemu/KVM on Linux, where Intel VT-x or AMD SVM hardware extensions are used to implement Type-1 virtualisation.

deleted 6y ago
[deleted]
alibert 6y ago
Unless I'm terribly wrong, when Hyper-V is enabled, it converts the current host Windows to a "Parent partition". This is what it's described here: https://superuser.com/questions/836116/hyper-v-appears-to-runs-on-top-of-the-host-os-so-why-is-it-considered-a-native https://superuser.com/questions/836116/hyper-v-appears-to-ru...

megavolcano 6y ago

The thing about Type 2 virtualization not working is true, but if you hyper-v enabled you already have type-1 virtualization so type 2 is kinda irrelevant. I've been using Hyper-V for about 5 years and never noticed any performance impact worth mentioning. Type 1 hypervisor VMs are still technically running on the metal.

galkk 6y ago

VMWare has beta Workstation that integrates with Hyper-V.