I have a 160 gb wd hd and an 80 gb wd hd. I was told that i would be better off (would be faster) connecting them through a pci card to my motherboard. I also want to connect an extra cdrw (i have a dvd +- burner and a dvd rom), and need the extra connection so it makes sense to me. I am unsure what type I need the pci 133 or pci100, as i do not know if the pci 100 supports hd that are bigger than 137gb? someone please help!