CPU charge with virtualbox

[neophus]

Hello all

I need help with virtualbox, I've a virtual machine with windows 10 and the host is linux mint 17.
I see when I launch windows with virtualbox I have a strong charge, more o less 50-60% of the CPU and time to time it goes until 100% and more.
Just before I was using ubuntu with virtualbox and windows and I decided to change for linux mint, thinking it could be better but I see that's the same thing.
I've an ASUS republic of gamers (geforce GTX 660, i7, 8 go ram) and I don't know what happened, I used the same thing there is 4 years ago (virtualbox/ubuntu) and It worked perfectly.
In my virtualbox configuration I use 4 processors and 4 go ram.

What could be the problem?

thanks

[scottgus1]

I7's usually are 4 physical cores with hyperthreading. Some gurus here say that hyperthreading doesn't count when counting cores, so your host CPU really has only 4 cores. You have 4 cores in the guest, so the guest can try to take all four cores from the host, leaving the two OS's fighting each other. The guest can easily get by with two cores, or even one.

There's a slight bit of host CPU overhead, too, when letting a guest have more than one core. And of course Windows Updates slams the CPU for a while, which may be the issue too.

Try a temporary new Windows 10 guest with two cores, and another temporary guest with just one core, and see what you get.

[neophus]

thanks for your answer but if I put 1 or 2 core in virtualbox configuration it's sufficient right? I don't have to do other installation?

[scottgus1]

You should be just fine trying it, but if you back up the guest, then you will be just fine trying it. See "Moving a VM" viewtopic.php?f=35&t=55003 and re-interpret it as "Backing Up a VM".