I'm reading an article on the DDR2 Memory, and now I'm totally confused. What does this line means
"Since the DDR2 internal clock runs at half the DDR external clock
rate, DDR2 memory operating at the same external data bus clock rate
as DDR results in DDR2 being able to provide the same bandwidth but
with higher latency."
- What is the difference between Internal and External clock rate in
reference to the RAM?
- What is I/O clock rate, Memory clock rate and Bus clock rate ?
This is a comparison chart of different types of RAM from the Wikipedia .
Module type ChipType Clock speed Bus speed
Transfer rate (byte/s)
PC2-6400 DDR2-800 400MHz
800 MT/s 06.4GB/s
PC3-6400 DDR3-800 400MHz
800 MT/s 06.4 GB/s
How can be the transfer rate of DDR2 and DDR3 RAM with the same clock speed of 400 MHz are same ?