So as I understand Argon2 is a memory-hard function, in other words it has to use a certain amount of memory, thus making it effective against GPUs.
So would this in theory, make Argon2 useless against an adversary with infinite memory?
But also if this is the case, then why does giving Argon2 a higher memory requirement also make it slower? Shouldn't it just take the same time but with more memory? Is there some more processing going on too? Or is it slower because of RAM read/write times?