With the Dark Base Pro 900, be quiet! has yet another case in its portfolio, while this is actually the successor of the Silent Base 800, which was introduced almost two years ago. This new flagship model is compatible with E-ATX motherboards and high-end custom water cooling gear. On top of that there is a lot of space for HDDs and SSDs.
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips