HI. This is my first post @ anandtech
I have a question about memory bandwidth. I thought it was a relatively simple calculation at first, but then I came across a whole bunch of information on the topic that has made me very confused.
I understand that a Byte is 8 bits and its almost like my understanding has failed form that point forward.
Here is a typical example of my problem:
DDR400 = 200MHZ
200MHZ x 8-bits = 1600Mbps
1600Mbps x 2 (double data rate) = 3200Mbps
So that 3200Mbps is what? Peak bandwidth? Transfer Rate? Theoretical Bandwidth? Transfer Speed? WHAT IS THE DIFFERENCE?
To compound issues even further, almost at the bottom of this website there is a chart showing the peak bandwidth of various memory products. Under DDR400 it shows the Peak Bandwidth to be .8Gb/s (800Mbps). So how the hell was that calculated? Shouldnt it be 3200 like I though above? WHAT AM I MISSING?
So someone PLEASE PLEASE PLEASE help me out here. Give me a detailed and clear explanation of how the various numbers are calculated, PLEEEEEEEEEEASE.
Thankyou so much if ur able to help my noob-self out,
oopyseohs

I have a question about memory bandwidth. I thought it was a relatively simple calculation at first, but then I came across a whole bunch of information on the topic that has made me very confused.
I understand that a Byte is 8 bits and its almost like my understanding has failed form that point forward.
Here is a typical example of my problem:
DDR400 = 200MHZ
200MHZ x 8-bits = 1600Mbps
1600Mbps x 2 (double data rate) = 3200Mbps
So that 3200Mbps is what? Peak bandwidth? Transfer Rate? Theoretical Bandwidth? Transfer Speed? WHAT IS THE DIFFERENCE?
To compound issues even further, almost at the bottom of this website there is a chart showing the peak bandwidth of various memory products. Under DDR400 it shows the Peak Bandwidth to be .8Gb/s (800Mbps). So how the hell was that calculated? Shouldnt it be 3200 like I though above? WHAT AM I MISSING?
So someone PLEASE PLEASE PLEASE help me out here. Give me a detailed and clear explanation of how the various numbers are calculated, PLEEEEEEEEEEASE.
Thankyou so much if ur able to help my noob-self out,
oopyseohs