title: Amd64 - segments and their limit: just 4Gb?
body: <p>I am on the amd64 arch, on intel c2d.</p>
  
  <p>I can't understand something simple :</p>
  
  <p>A segment descriptor is a the representation of a process (code segment, data, stack..)</p>
  
  <p>How is it that we are stil limited to 4Gb on the amd64 architecture (that is the limit field in the descriptors).</p>
  
  <p>Should it be 64bit limit and not a 32bit one ?</p>