Advances in multi-gigabit data transfer have been dominated by serial data technologies like USB, PCI Express, and Serial Attached SCSI.  Now, as we leap another order of magnitude in data rate from the 3rd generations of serial technologies like USB3 and PCIe Gen to 40 and 100 Gb/s Ethernet, parallel architectures are coming back. The most ambitious is 100 GbE’s four lanes at 25 Gb/s each. In this paper we start with a quick, high level view of the emerging multi-Gb/s architectures and then delve into the tricks that make them work and how to analyze them.