An Even Easier Introduction to CUDA (Updated)
A Typical GPU Programming (blog draft)
The Graphics Processing Unit (GPU)1 provides much higher instruction throughput and memory bandwidth than the CPU within a similar price and power envelope.
This difference in capabilities between the GPU and the CPU exists because they are designed with different goals in mind. While the CPU is designed to excel at executing a sequence of operations, called a thread, as fast as possible and can execute a few tens of these threads in parallel, the GPU is designed to excel at executing thousands of them in parallel (amortizing the slower single-thread performance to achieve greater throughput).
CPU: thread 수십개
GPU: Thread 수천개