Qubes OS on 8G Ram HP w Hypervisor but

I have only qubes running on my hp pavilion g series/8 g ram( instead of 16min)/ virtualization, but I still get the following error msg when I try to start a cube; “Failed to start an HVM qube with PCI devices assigned-hardware does not support IOMMU/VT-d/AMD-Vi”
Since my laptop has virtualization enabled, I am not sure why.
The import question I have for the instructor @NathanHouse is, what percentage of qubes benefits will I enjoy if I do not fix the error msg and improve ram to 16? In other words, can I use qubes reasonably this way or I just cannot?

I found similar error being discussed on qubes forum. You should check that out - "Failed to start an HVM qube.." - User Support - Qubes OS Forum