How much RAM for Full Internet tables

Hello, Is anyone here know, how much RAM needed for BIRD to receive all full routes Internet table? My bird consumes around 20G of RAM for just 1 full routes 800k total used free shared buff/cache available Mem: 31G 20G 9.4G 1.2M 1.6G 27G Is this as expected ? or we can fine-tuning Bird ?