DDR2 memory has a DDR number and a PC number.

[MplsBob]

A DDR2 memory is described with a DDR number and a PC number.

What does each of those numbers mean?

 

[Pabster]

Originally posted by: MplsBob

A DDR2 memory is described with a DDR number and a PC number.

What does each of those numbers mean?

Wiki is your friend

 

[PurdueRy]

Originally posted by: MplsBob

A DDR2 memory is described with a DDR number and a PC number.

What does each of those numbers mean?

the number after PC is the bandwidth. The number after DDR is the bus speed

 

[MplsBob]

Thank you Pabster & PurdueRy.

A PC2-6400: DDR2-SDRAM memory stick specified to run at 400 MHz does two transfers per clock cycle so it requires DDR2-800 memory chips. Since there are eight bytes (64 bits) per transfer, you have the following math for this case:

bandwidth= 400MHz*2 transfers per clock * 8 bytes per transfer= 6.400GB (note the decimal point)

So this memory can be specified correctly as either DDR2-800 Memory or as memory having a bandwidth of 6.400GB, normally written as PC2-6400 memory.

Having gone through all of this, if you take the memory speed and multiply it by eight you have the bandwidth.

In this case, 800 Mhz Memory speed * 8= PC2-6400.


MplsBob