The dell will definitely need the new case since I am sure any non-dell motherboard probably won't fit. As for the 4x AGP, it isn't a big setback. You shouldn't notice too much of a difference at all. If you really wan't the absolute most out of your card then you can get a new motherboard, but it's really up to you if the money for a new one will justify not a whole lot of improvement, if any... depending on what you are doing. If you are looking into a new mobo go with ASUS or ABIT, they are both respectible companies that you can trust for a good product. The best prices and service are usually from Newegg.com, if you havn't checked that out yet you can compare products there.
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