My laptop has a 4GB RAM module and a 2GB module, so only 4GB can work in dual channel mode. The system usually uses about 3GB, but when I'm running a VM, it uses around 5GB. Is it likely that this is why my VM is so sluggish?
(I'm not sure whether this is a RAM question or a virtualization question.)
You only have 6 GB to work with, so it is only natural that your virtual machines are "sluggish".
Whereas a Linux or Windows XP VM can work quite nicely with just 1 GB virtual RAM, a Windows 7 or later requires much more to really work.
An extract from a Ten Forums tutorial Hyper-V - Optimizing Virtual Machines:
Kari
6.1 The ideal settings for a VM is a subjective thing, based on multiple factors. The recommendations in next step are based on following factors:
- Windows 10 x64 host
- 16 GB RAM
- 8 logical processors
- An SSD and an HDD
- Guest (VM) OS Windows 10 x64
6.2 For those specs, my recommended settings for a Windows 10 VM which I have found to be quite good are as follows:
- 4 GB vRAM
- 4 vCPU
- Disable Secure Boot
- Production Checkpoints
- Disable Automatic Checkpoints
- Install on Differenicing disks, Parent Disk on SSD
6.3 It is extremely important to let host have enough resources to run smoothly. Never run virtual machines with less than 2 GB available for host. That is the absolute minimum, I recommend always having at least 4 GB for host.
What this means is that if you only have 4 GB of RAM, never assign more than 2 GB for a VM, and from 8 GB RAM, never more than 4 GB.
I run my Hyper-V virtual machines having parent disks on SSD, and child disks on external USB 3 HDD. They are quite fast.
Hyper-V - Use Differencing Disks
Kari
Well, my comments were based on one of my laptops with 8GB RAM and an HDD. When the HDD started showing SMART reallocation events I replaced it with an SSD and restored its Macrium image. The performance improvement for windows was noticeable, but the performance improvement for its VMs was phenomenal.
Hi folks
I'd go for as much RAM as possible when using VM's -- even though modern VM systems dynamically allocate and release RAM for the guest as and when needed .
W10 will actually run OK on 2GB RAM in a Virtual machine -- depending on of course what applications are themselves running on the VM -- and of course don't forget that the more the HOST is also running concurrently will influence the behaviour of the VM's.
An 8GB laptop should be fine for running certainly 1 Windows 10 VM - certainly if the OS (Host) is on an SSD -- I've had some VM's on external USB HDD's which have performed quite adequately -- If the Host has only 4GB RAM then forget the whole idea of Virtual machines apart from testing some Linux distros which can run in tiny amounts of RAM.
So rule should be -- minimum of 8GB RAM and HOST OS on an SSD, don't run too much on the HOST while VM is running and obviously don't overload the VM by trying to run too much on it either unless you can give it a lot of resources.
For HYPER-V the best way if you can (not really possible on a laptop though) is to passthru hardware like Graphics, network card and HDD/SSD that the GUEST is running on - that way you are using the OS's native systems which usually should yield better performance than using "paravirtualised" hardware -- the use of paravirtualised hardware means that the VM can generally be used on all sorts of real hardware without modification - e.g VMWare VM's don't need any change at all when switching machines or even HOST OS's -- but this comes at a performance price of course.
Cheers
jimbo
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