Maybe because CPUs are no longer competitive. A Bitcoin miner is essentially cracking a SHA256 hash (with zeros added for difficulty control). GPUs are 20-50 ti

Maybe because CPUs are no longer competitive. A Bitcoin miner is essentially cracking a SHA256 hash (with zeros added for difficulty control). GPUs are 20-50 times more efficient power-wise than CPUs at this task. Interestingly, the AMD architecture adds a factor of 3-5 in the mix, compared to NVidia. http://webcache.googleusercontent.com/search?q=cache:FSUbAiIxrU0J:https://en.bitcoin.it/wiki/Why_a_GPU_mines_faster_than_a_CPU+bitcoin+mining+amd+nvidia&cd=1&ct=clnk http://webcache.googleusercontent.com/search?q=cache:FSUbAiI... For a more detailed comparison: http://webcache.googleusercontent.com/search?q=cache:9FiOofDGPJAJ:https://en.bitcoin.it/wiki/Mining_hardware_comparison+bitcoin+mining+hardware+comparison&cd=1&ct=clnk http://webcache.googleusercontent.com/search?q=cache:9FiOofD... Note that a PS3 Cell processor falls somewhere between a CPU and a GPU: