Theoretically it should work. However some of the old PCI-E 1.0 slots have had issues with the PCI-E 2.1 cards, it's possible those old slots may have problems with the 3.0 cards. Nobody has really tested brand new video cards with those older systems so it may or may not work. If it doesn't work check the motherboard manufacturer's website for a BIOS update that addresses PCI-E compatibility issues. I'd say go ahead and order the 3.0 card, but be prepared to RMA it if you have problems and there is no BIOS update to address the issue.