It says that multi-core system with certain hardware can benefit from this update, but it doesn’t actually say which hardware is needed. 
I believe that the improvement is called “enabling ntuple offloading” - found from this commit.
https://git.ipfire.org/?p=ipfire-2.x.git;a=commit;h=8be8ac63cafef9952f35c4b87883135e1b33ca4d
You need to find network cards/drivers that have support for this ntuple offloading.
According to the announcement, if your hardware is capable it will automatically be used.