I recently bought a cheap NIC which I think has a x8 PCI slot. On the box it says: "Compatible with PCI revision 2.1/2.2/2.3".
I want to use this in the MSI H81M-E34. On the site from MSI it says that the motherboard has 1x PCI 2.0 x16 and 2x PCI 2.0 x1 slot.
I searched on the web and almost everybody says that it's backwards compatible but it will not fit in either the x16 or x1 slots.