We have fabricated an LUT-based FPGA device with functionalities measuring within-die variations in a 90nm process. Measured variations are used to configure each device to maximize the operating frequency by allocating critical paths in faster portions. Variations aremeasured using ring oscillators implemented as a configuration of the FPGA. Placement optimization using a simple model circuit reveals that performance of the circuit is enhanced by 4% in average, which is the same amount as the measured within-die variations. The yield is enhanced by 32% to the worst case.