In this paper, two performance metrics power and delay are estimated for various XOR-XNOR circuits and Multiplexer for designing 4-2 compressor. The main objective is to design an energy efficient compressor for computing applications in FIR filter. The simulations for the designed circuits performed in cadence virtuoso tool with 45 nm CMOS technology at a supply voltage of 0.9 Volts. The proposed 4-2 compressors consist of six blocks out of which two XOR-XNOR blocks and four MUX blocks. The average power, delay and energy consumed by the proposed compressor which is based on 5T XOR-XNOR and GDIMUX design is 85.72 nW, 62.53 pS and 5.36 aJ respectively