Well, on e.g. x86 you have "rep stos" instruction which pretty much amounts to memset in HW.
The operation needs to be blocking otherwise you could of course do it without CPU at all (DMA). But you still have to go through the memory controller and actually write each word of memory.
The operation needs to be blocking otherwise you could of course do it without CPU at all (DMA). But you still have to go through the memory controller and actually write each word of memory.