[GTALUG] QEMU vs VirtualBox -- which is faster?

I'm running Kubuntu 26.04 inside QEMU and VirtualBox.  Now, QEMU (with KVM enabled, --enable-kvm) is supposedly be faster, but strangely it seems slower to me.  I am compiling kernel now, but that takes 2 hours on 2 cpu, which mean I have to wait 4 hours to find out. Is there a quick way to test cpu/ram/disk, by "quick", I mean 5min max?