>"Key to PCIe’s approach is the use of “lanes” of data transfer speed, allowing high-speed cards like graphics adapters more bandwidth (up to 16 lanes) and slow

>"Key to PCIe’s approach is the use of “lanes” of data transfer speed, allowing high-speed cards like graphics adapters more bandwidth (up to 16 lanes) and slower technologies like network adapters or audio adapters less. This has given PCIe unparalleled backwards compatibility — it’s technically possible to run a modern card on a first-gen PCIe port in exchange for lower speed — while allowing the standard to continue improving." Backwards compatibility -- seems to have been the key to Microsoft Windows OS's popularity as well... Anyway, an excellent computer history article!