By this process we can find out how many bytes can be transferred per second between the memory controller and the memory module
. This is based on the assumption that the data will get transferred on every single clock pulse. In order to arrive at the maximum theoretical transfer rate in MB/s i.e megabytes per second we can multiply the DDR clock in MHz by eight. For instance the DDR2-800 memories would have a maximum theoretical rate of 6400 MB/s by following the maths 800x8. The memory modules that use this kind of memory are called PC2-6400. These numbers can be understood as maximum theoretical numbers that can be never reached. It is because it doesn't really happen that the memory sends data to the memory controller every single clock cycle. It is important that the memory controller and the memory exchange their commands of instructing the memory to deliver data stored at a stated position. It is during such time that the memory won't transfer the data.