There's a list of motherboards I've seen searching on newegg with slots such as 64-bit/100MHz PCI-X. What is the use of this slot? What is the use of PCI 1x slots, and why do the new boards with PCI 16x have them? The only use I've seen of the 1x slots is an old AOpen 56K modem in my cousin's obsolete computer. Also, what does Dual-Channel Memory actually do for you?