title: cpu vs gpu - when cpu is better
body: <p>I know many examples when GPU is much faster than CPU. But exists algorithms (problems) which are very hard to parallelise. Could you give me some examples or tests when CPU can overcome GPU ?</p>
  
  <p>Edit:</p>
  
  <p>Thanks for suggestions! We can make a comparison between the most popular and the newest cpu's and gpu's, for example Core i5 2500k vs GeForce GTX 560 Ti. </p>
  
  <p>I wonder how to compare SIMD model between them. For example: Cuda calls a SIMD model more precisely SIMT. But SIMT should be compared to the multhitreading on CPU's which is distributing threads (tasks) between MIMD cores (Core i5 2500k give as 4 MIMD cores). On the other hand each of these MIMD cores can implement SIMD model, but this is something else than SIMT and I don't know how to compare them. Finally a fermi architecture with concurrent kernel execution might be consider as MIMD cores with SIMT.</p>