@dyn not understanding specs or not, practical experience shows me that dual cores are not ideal for running a VM. A recent case on a freshly installed 2013 13" running Win 10 is an absolute pain - for simple word processing, excel sheets etc. Newer Airs are okay for the basics, if your usage is light and so is the OS, e.g. XP. Again, all practical experience.
That is not normal behaviour, something is seriously wrong. Usually these things are caused by people not understanding virtualisation and simply assigning way too many resources to the vm (somehow many people seem to think they have to assign all the cores of the physical CPU to the vm...the only thing that does is wreak absolute havoc regarding performance). The workload you are describing here should work fine on a 2006 MacBook with only 2GB of RAM!
Check the assigned resources and make sure you have installed the guest additions/tools. Stick to the defaults when creating a vm.
Again my practical experience says that I'd rather use Crossover alone if I could - the pain of running an entirely separate OS for tasks such as Visio, MS Project or some word processing, etc. is certainly not worth it. Power consumption, disk & memory usage, not to mention needing anti-virus software & perpetual updates...way more of a headache than using Crossover.
Lots of misconceptions there I see. Antivirus products have been on auto-update for years. The moment you have an internet connection will be the moment they start checking for updates (and pull if there is any). Windows has been on auto-update as well, especially since version 8 (people are actually criticising that they can't turn it off). You'd have to go and turn it all off (which is a complete migraine attack with Windows 8 and up) before it can even become a headache.
In most scenarios the resource usage of a vm is higher than when using Crossover but the main reason why Crossover is an issue is that it has to fully support the software you want to run which it doesn't in most cases. You really have to check the compatibility list first and read the comments there and only use the version of the software that is listed there as working. Use a newer version (which quite a lot of people do with Adobe and Microsoft software since the subscription licensing) and things will fall apart. You don't into this when using a vm.
So, my advice to someone considering a new Mac for virtualisation is as follows. If you go the dual-core route, test it thoroughly during the return window - you don't want to be stuck with a machine for a number of years that's a pain to use and ultimately not up to the task.
My advice to anyone considering virtualisation: read up on what it is and how you use the software but most off all: don't ever change the defaults unless you absolutely know what you are doing! For 99% of the users it doesn't matter what CPU (dual core or quad core) is in the machine.
You are completely right. Using a dual-core ThinkPad at the moment, it isn't able to handle a single VM properly...
With Linux as host, its slow, but at last it works in a way. Running Windows as host, no VM is possible, the machine just isn't able to handle it...
Now waiting for the 2017-MBPs and I will buy a 15" model.
Don't bother waiting because it won't run on that machine nor on the 2019, 2020, etc. models because you clearly messed something up. The current and previous dual core models are perfectly fine running multiple Linux vm's. CPU is hardly an issue with virtualisation, the most important things are memory and I/O. VMware has done some research on this topic and made a whitepaper about it. Sysadmins running various hypervisors are also seeing this same behaviour.
As stated above, people who have performance issues usually have caused this themselves by assigning way too many resources to the vm; usually this is the amount of vCPUs. A rule of thumb here is that one cannot assign more than half the physical resources to the vm's because the other half is required for the host OS. That means that if you have a quad core CPU you can assign no more than 2 vCPUs to a vm. However, due to the way the hypervisor is handling the resources that the host OS assigns to it you can run more than 1 vm with such a setting. In other words: running 1 vm with 4 vCPUs is not possible but running 4 vm's with each one of them assigned 2 vCPUs is not a problem.
Virtualisation == resource management! Even with Virtualbox, Parallels, Fusion/Workstation, not just the big stuff.
My dual core 13" MBP 2016 can run 12 vm's quite easily. These vm's range from clients running Windows 10, Ubuntu 16.04.2, openSUSE Leap 42.2, couple of macOS ones to servers running on Debian 8 and FreeBSD 10. No problem with 16GB memory and the 1TB disk (the other SSDs will work just as well). Btw, I use VMware Fusion Pro 8.5 to do all this and use open-vm-tools in the unix/linux vm's because I like it better than the supplied VMware Tools (it comes with the package manager of the OS which makes it easier to install with unattended installations plus it also plays nice with kernel updates).
Oh and another thing to mention: Virtualbox is free but it is also well known to be the slowest hypervisor on macOS as well as it having I/O issues (I/O can be very slow at times). Ditching that for Parallels, Fusion or even hypervisor.framework can make all the difference.