I'w writing all this from memory, so wait til someone confirms (or not)...You can also use an adaptor : <a href="http://www.adexelec.com/pciexp.htm#PEXP4-SX-4/1Found">http://www.adexelec.com/pciexp.htm#PEXP4-SX-4/1Found</a> a link with specs : <a href="http://zone.ni.com/devzone/cda/tut/p/id/4037(scroll">http://zone.ni.com/devzone/cda/tut/p/id/4037(scroll</a> down the page, there is a chart that shows what card you can put in what motherboard PCIe slot)Summary : As mentioned above, plugging a x4 PCI Express board into an x8 sl