 Write-combining does not guarantee that the combination of writes and reads is done in the expected order.For example, a Write/Read/Write combination to a specific address would lead to the write combining order of Read/Write/Write which can lead to obtaining wrong values with the first read (which potentially relies on the write before).In order to avoid the problem of read/write order described above, the write buffer can be treated as a fully associative cache and added into the memory hierarchy of the device in which it is implemented.