I know there is not a whole lot of difference between x4 and x8 PCI-E bandwidth however I cannot say how it would affect when in CF mode it could be a whole new story when 2 lanes are in use at the same time. http://www.youtube.com/watch?v=rSfifE2Domo&feature=relmfu
Em.. The first lane was running on x16 not x8 in case you misunderstood the question. I'm at my office now and youtube is out of reach. lol.. will check back later at home.. thanks.