PCB materials directly influence attenuation and NEXT/FEXT crosstalk signal integrity of an ATE loadboard design. Balancing performance, cost, and ease of fabrication requires a quantitative understanding of the impact that the dielectric material has on the performance of a multi-gigabit loadboard signal path. An understanding of how the material will perform when used to fabricate 20+-layer-count ATE boards with thicknesses of more than 200 mils is required. This paper provides an analysis of various loadboard PCB materials for a nominal loadboard test fixture design with 10 inches of path length and data rates up to 43 Gbps.