What advantage is there in connecting the cable modem via USB vs pci card?
The USB port is controlled mostly by the processor, which means that if there is any activity on the USB port, the CPU has to take time to process it. A NIC card has it’s own processor, so it will do all the processing and just hand the data to the CPU or show it into memory without the CPU needing to do any work. Basically, PCI is more efficient, but in most mid to high end computers, you won’t notice much of a difference.