Inferior VM performance is usually because the guest is running in "HVM" mode
(Hardware Virtualized Mode, or Fully-Virtualized Mode). While this may allow
you to run an unmodified system in a virtual machine, all of the I/O devices are
emulated in software. So, if you use a network interface card (NIC) a device
driver in the guest communicates with a driver in the host system running VBOX;
this driver pretends to be a network interface card, responding to
register-level reads and writes. Once the emulated NIC software decides what
the VM guest really wants, it forwards a request to the actual device driver in
the VBOX host. Sound inefficient? You bet it is.
To improve the situation, VBOX provides "Guest Additions" for most guest O/S's.
These are actually some relatively simple device drivers that know how to
communicate with the host's device drivers using high-level commands instead of
hardware register reads and writes. Using these para-virtualization drivers,
you should get only a few percent performance degradation over a bare-metal
You may want to try Oracle VM which installs onto bare-metal and supports both
Linux and Windows guests. Para-virtualized add-on drivers are available for
Windows. There are even pre-configured Linux templates similar to VMWare
appliances. No pre-configured Windows because it isn't redistributable, but
add-on drivers are available. Check it out at http://www.oracle.com/oraclevm,
it's free to download and free to use. Commercial support is available.