That question doesn't make any sense. They don't do the same thing, so you can't compare their relative performance. What's faster: an Intel i7 or a BMW i8?
Malloc is potentially troublesome for two reasons. First, its performance is potentially unpredictable. It depends on the current state of the heap at the time of the call, which you can't know in advance except in some very rare situations. It can also fail entirely, and that is likewise unpredictable.
memcpy and memmove, ultimately being byte-copying loops, don't suffer from these problems. Their performance is consistent and they always succeed if your pointers and lengths are valid.
On PCs these days, the troubles of malloc don't matter much. You have so much performance margin that occasional slow calls don't matter, and virtual memory with a big address space means that it almost never fails. If it does fail, it's OK if the program crashes and you have to restart it. But many systems are much more constrained.
Malloc is potentially troublesome for two reasons. First, its performance is potentially unpredictable. It depends on the current state of the heap at the time of the call, which you can't know in advance except in some very rare situations. It can also fail entirely, and that is likewise unpredictable.
memcpy and memmove, ultimately being byte-copying loops, don't suffer from these problems. Their performance is consistent and they always succeed if your pointers and lengths are valid.
On PCs these days, the troubles of malloc don't matter much. You have so much performance margin that occasional slow calls don't matter, and virtual memory with a big address space means that it almost never fails. If it does fail, it's OK if the program crashes and you have to restart it. But many systems are much more constrained.