title: What's the size of a QWORD on a 64-bit machine?
body: <p>I'm currently looking to find an answer to the above question. So far I found people saying, that the word size refers to the size of a processor register, which would suggest on a 64-bit machine the word size being 64 bits and thus a QWORD (4 * word) being 256 bits in size.</p>
  
  <p>But on the other hand I found sources like <a href="http://edwin-wang.com/2012/02/bit-nybble-byte-word-dword-qword/" rel="noreferrer">this</a> saying the size would be 128 bits (64 bits for 32-bit and doubled this for 64-bit), while even then others suggest the size would be 64 bits. But the last one is somehow related to Microsoft making matters worse by confusing everyone by defining the size of a word being 16 bits.</p>
  
  <p>Maybe someone could solve my confusion and enlighten me on this topic.</p>