Yes, match the speed and timings and the amounts can be any accepted sizes, 1GB, 2GB, 4GB, 8GB, 16GB? in pairs. First pair in A1 and B1, and second pair in A2 and B2. 4x 1GB for 4GB total, 2x 1GB and 2x 4GB for 10GB total, including your 2x 4GB and 2x 8GB for 24GB total.