When selecting instruments for use in an automated testing environment, the engineer is presented with numerous options. The make, model, feature set, and reliability of each device are common factors in this decision. However, the type of bus over which the instrument communicates is what often governs the ultimate decision. An Ethernet-based system may be selected because of the high speed it affords, while a GPIB-based setup may be selected due to the vast selection of devices available that use this type of interface. This paper presents the advantages of using PXI devices in conjunction with IVI drivers, which include compact size, ease of integration, and cos effectiveness. This paper then provides empirical data comparing the performance of PXI against that of GPIB. It also demonstrates how IVI technology facilitates the design of a system containing devices of several different interfaces.