title: How come register file size in GPU's (eg GTX 1080) bigger than L2 cache size?
body: <p>Looking at this fact, I've started wondering how registers work in GPU? Before knowing this, I thought going higher and higher above the hierarchical memory ladder, the size keeps on decreasing (which is intuitive (latency decrease, size decrease)). What is the purpose of registers in GPU's and why is their size greater than the L2/L1 cache?
  Thanks.</p>