Memory timing examples

Memory timing examples (CAS cessation only) Generation Type Data amount Bit time Command amount Cycle time CL First chat Fourth chat Eighth word

SDRAM PC100 100 MT/s  10 ns 100 MHz  10 ns 2 20 ns 50 ns 90 ns

PC133 133 MT/s  7.5 ns 133 MHz  7.5 ns 3 22.5 ns 45 ns 75 ns

DDR SDRAM DDR-333 333 MT/s  3 ns 166 MHz  6 ns 2.5 15 ns 24 ns 36 ns

DDR-400 400 MT/s  2.5 ns 200 MHz  5 ns 3 15 ns 22.5 ns 32.5 ns

2.5 12.5 ns 20 ns 30 ns

2 10 ns 17.5 ns 27.5 ns

DDR2 SDRAM DDR2-667 667 MT/s 1.5 ns 333 MHz  3 ns 5 15 ns 19.5 ns 25.5 ns

4 12 ns 16.5 ns 22.5 ns

DDR2-800 800 MT/s  1.25 ns 400 MHz  2.5 ns 6 15 ns 18.75 ns 23.75 ns

5 12.5 ns 16.25 ns 21.25 ns

4.5 11.25 ns 15 ns 20 ns

4 10 ns 13.75 ns 18.75 ns

DDR2-1066 1066 MT/s  0.95 ns 533 MHz  1.9 ns 7 13.13 ns 15.94 ns 19.69 ns

6 11.25 ns 14.06 ns 17.81 ns

5 9.38 ns 12.19 ns 15.94 ns

4.5 8.44 ns 11.25 ns 15 ns

4 7.5 ns 10.31 ns 14.06 ns

DDR3 SDRAM DDR3-1066 1066 MT/s  0.9375 ns 533 MHz  1.875 ns 7 13.13 ns 15.95 ns 19.7 ns

DDR3-1333 1333 MT/s  0.75 ns 666 MHz  1.5 ns 9 13.5 ns 15.75 ns 18.75 ns

6  9 ns 11.25 ns 14.25 ns

DDR3-1375 1375 MT/s  0.73 ns 687 MHz  1.5 ns 5  7.27 ns  9.45 ns 12.36 ns

DDR3-1600 1600 MT/s  0.625 ns 800 MHz  1.25 ns 9 11.25 ns 13.125 ns 15.625 ns

8 10 ns 11.875 ns 14.375 ns

7  8.75 ns 10.625 ns 13.125 ns

6  7.50 ns 9.375 ns 11.875 ns

DDR3-2000 2000 MT/s  0.5 ns 1000 MHz  1 ns 10 10 ns 11.5 ns 13.5 ns

9 9 ns 10.5 ns 12.5 ns

8  8 ns 9.5 ns 11.5 ns

7  7 ns 8.5 ns 10.5 ns