All of the recent technology releases from the PCI-SIG are built to 3.3V. What is happening with 5.0V?
The PCI-SIG believes that migrating to 3.3V signaling is keeping pace with the industry’s migration to 3.3 volt technologies and the need for higher performance within the system. Both high-end and mobile environments currently implement 3.3V signaling (no 5.0V) and this trend will soon migrate to the workstation and desktop level (3.3V signaling will replace 5.0V signaling when the newer technologies can no longer support 5.0V signaling).