Virtualbox's Performance Effects on the Host System

[jimmmmy]

Hi all,
I have some technical questions about the Virtualbox.
We are planning to use Virtualbox to run a linux guest on our Windows 7 host system. We will be also running some other data sensitive applications on our Windows 7 host which will be heavily using serial port and ethernet communication.
We are worried whether virtualbox can have effects on the host system applications in terms of performance. We know that Virtualbox comes with several kernel drivers (VBoxDrv, VBoxNetFlt, VBoxNetAdp, etc).

Does VBoxDrv driver effect the performance of host system even the VirtualMachine is not running? (e.g. intercepting/filtering any interface even VM is not running). Is it active in none of VMs are running?

We will have some applications on the host that will be heavily using serial port(COM1). But we will be not using serial port on the guest. Does our running VM affect the performance of serial port communication (especially timing) of host applications? (serial port is not selected in guest configuration) Does VirtualBox intercept serial communication even the VM is not using serial port communication? or only filters it when guest is configured to use serial port?

We will be using NAT mode in our VM but Virtualbox will be installed with also Host-Only and Bridge drivers (in case we may need them in future) support. Does installing VirtualBox with Host-Only and Bridge mode support have any effect on the network performance of the applications running on the host system (running VM is only configured in NAT mode)? Can they cause to drop some packages on the host system?

Thanks in advance.

[jimmmmy]

BTW, we will not use USB on guest and VirtualBox will be installed without USB support.

[socratis]

Does VBoxDrv driver effect the performance of host system even the VirtualMachine is not running?

No, simply installing a kernel driver doesn't mean that it's always active, it means it's always available and it works/filters only when asked to by an application (VBox).