Described herein is an apparatus for dynamically adjusting a voltage reference level for optimizing an I/O system to achieve a certain performance metric. The apparatus comprises: a voltage reference generator to generate a voltage reference; and a dynamic voltage reference control unit, coupled with the voltage reference generator, to dynamically adjust a level of the voltage reference in response to an event. The apparatus is used to perform the method comprising: generating a voltage reference for an input/output (I/O) system; determining a worst case voltage level of the voltage reference; dynamically adjusting, via a dynamic voltage reference control unit, the voltage reference level based on determining the worst case voltage level; and computing a center of an asymmetrical eye based on the dynamically adjusted voltage reference level.