Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Root complex
open-in-new
<p>In a <a href="/facts/PCI_Express/ADhsLCUK">PCI Express</a> (PCIe) system, a root complex device connects the CPU and memory subsystem to the PCI Express switch fabric composed of one or more PCIe or PCI devices. A root complex is sometimes referred to PCI root bridge. </p><p>The root complex generates transaction requests on behalf of the <a href="/facts/CPU/Jxp1bqMV">CPU</a>, which is interconnected through a local bus. Root complex functionality may be integrated in the chipset and/or the CPU. A root complex may contain more than one PCI Express port and multiple switch devices can be connected to ports on the root complex or cascaded. </p>