Abstract: This disclosure relates to a computer system having a peripheral component interconnect (PCI) and expansion bus riser card having at least one expansion bus slot and at least one PCI slot, the latter of which meets a PCI bus stub length requirement. The PCI slot is connected to the PCI bus by a plurality of PCI stub lines. Each of the plurality of PCI lines does not exceed a predetermined length. The expansion bus is divided into a first section having a first plurality of lines and a second section having a second plurality of lines. The plurality of PCI lines are disposed between the first and second plurality of lines of the expansion bus such that all of the plurality of PCI lines from the riser card to the PCI bus do not exceed the predetermined length.