While Intel has offered good Ice Lake support since before the CPUs were shipping (sans taking a bit longer for the Thunderbolt support as a key lone exception, since resolved), a feature that’s been publicly known since 2017 is the Fast Short REP MOV behavior and finally with Linux 5.6 that is being made use of for faster memory movements…

Source: Phoronix – Linux 5.6 To Make Use Of Intel Ice Lake’s Fast Short REP MOV For Faster memmove()