If the motherboard supports dual channel memory, then yes, all things being equal, it should be faster since the memory path is 128 bits wide rather than 64 bits wide. In reality, you'll get anything from zero benefit to some benefit. The memory sticks have to be pretty much identical for dual channel to be enabled, which in practice means buying them at the same time. 1GB operating as dual channel probably won't be as useful as, say, more than 1GB of non-dual channel memory.