Difference between revisions of "Bitcoin and Litecoin Comparison"

For {https://en.bitcoin.it/wiki/Proof_of_work proof of work], Bitcoin uses the highly parallelizable SHA256 hash function, and therefore Bitcoin mining is a GPU-friendly task. Litecoin uses {http://www.tarsnap.com/scrypt.html scrypt] instead of SHA256 for proof of work. The scrypt hash function uses SHA256 as a subroutine, but it also depends on fast access to large amounts of memory rather than depending just on fast arithmetic operations, so it is hard to run many instances of scrypt in parallel by using the {http://en.wikipedia.org/wiki/Arithmetic_logic_unit ALUs] of a modern graphics card. GPUs still do prove useful for Litecoin mining, though the improvement over CPUs is less significant than it was for Bitcoin mining (e.g. 10x speedup instead of 20x speedup).

See also: {http://crypto.stackexchange.com/questions/400/why-cant-one-implement-bcrypt-in-cuda bcrypt in Cuda?],  {https://en.bitcoin.it/wiki/Why_a_GPU_mines_faster_than_a_CPU Why a GPU mines faster than a CPU], {http://en.wikipedia.org/wiki/Bcrypt bcrypt] (scrypt predecessor)