GPUs are not a solution to every problem. There are several problems currently: a) Explicit data copy required to and from GPU makes GPGPU useless for many pro

GPUs are not a solution to every problem. There are several problems currently: a) Explicit data copy required to and from GPU makes GPGPU useless for many problems. b) GPUs are not as general purpose as CPUs. For example, no indirect jumps (goto address x) is allowed so no real subroutine calls. And no recursion. c) GPUs are not good at branching. The toll on branching can be heavy. d) Caches are fairly small. The on-chip shared memory, which is essentially a software controlled cache is a good idea in some cases but its still of a very small size. Well the thing is that the computational peak power of the GPUs is not free. It comes at the cost of reduced flexibility. Nothing is free in computer architecture.