This work presents the gallium arsenide (GaAs) electro-optic absorption (EA) modulators performance evaluation compared to the previous models with SiGe EA modulators under high-temperature variations. The average switching speed is studied and analyzed for both EAs. The consumed energy or power per bit is taken into account for both modulators. The modulation depth and transmission coefficient are studied for both previous and proposed EAs with 250 Gb/s at room temperature. The technical performance parameters are also analyzed such as insertion loss, modulation depth, output power, contrast ratio, transmission coefficient, and power length product for both previous and proposed EAs under high-temperature variations. The study assured that to get the optimum GaAs EAs performance efficiency, the modulator length and the thickness should be values of 50 and 5 mm, respectively at room temperature.