1. Reference string: 1~200 2. Number of memory references: At least 20,000 times 3. Number of frames in the physical memory: 10, 20, 30, 40, 50 4. Two test reference strings: (1) Random: Arbitrarily pick one number for each reference. (2) Locality: Simulate function calls. Each function call may refer a subset of 1/4~1/2 string (the length of string can be random). 5. Hardware-supported bits: Reference bit and modify bit (1) Hardware will automatically set these two bits. (2) There is a probability p that a page in the memory will be modified. The value of p will be 0.05, 0.1, 0.15, 0.2, and 0.25.