dxo opticspro

Hi! I just exported the same RAW in DxO and LR to jpeg. Same settings, 90%, 300DPI. No correction except for the lens. DxO - 2.84 MB (2,979,156 bytes), LR - 4.96 MB (5,203,044 bytes). I did export a few more and DxO always gives me a much smaller files. Can someone please explain where is...