faster: Xen or qemu+kvm?

[Mihamina Rakotomandimby]

Hi,
Question for those who tried:
Who is faster: Xen or qemu+kvm?

The aim is to have the cleanest ubuntu as possible as host, and then
have WindowsXP, FedoraCore and Debian as guests. Never simultaneously.
I wont use graphical interface (except for Windows), just ssh.
I will package some home made soft for those distributions.
I have a VT CPU, 2GiB amount of RAM.

If you have any ratio available, event approximated, I would be
interested in.