title: Load/Store Units (LD/ST) and Special Function Units (SFUs) for the Kepler architecture
body: <p>In the <a href="http://www.nvidia.com/content/PDF/kepler/NVIDIA-Kepler-GK110-Architecture-Whitepaper.pdf" rel="nofollow noreferrer">Kepler architecture whitepaper</a>, NVIDIA states that there are <code>32</code> Special Function Units (SFUs) and <code>32</code> Load/Store Units (LD/ST) on a SMX.</p>
  
  <p>The SFU are for "fast approximate transcendental operations". Unfortunately, I don't understand what this is supposed to mean. On the other hand, at <a href="https://stackoverflow.com/questions/11554122/special-cuda-double-precision-trig-functions-for-sfu">Special CUDA Double Precision trig functions for SFU</a> it is said, that they only work in single precision. Is this still correct on a K20Xm? </p>
  
  <p>The LD/ST units are obviously for storing and loading. Is any memory load/write required to go through one of theses? And are they also used as a single warp? In other words, can there be only one warp which is currently writing or reading?</p>
  
  <p>Cheers,
  Andi</p>