Ram Question?

[808Alaska]

I got a question, when looking at different types of RAM for PC's i see that it has two different numbers for the speeds. one of then is the MHz which i understand, but the one i dont understand is the PC-5400 or like PC2-6500 or something like that.
Could some one please explain to me what this speed rating is of, and how its calculated. thanks you.

 

[Hefemeister]

the number pc3200 is the maximum transfer rate in MB/sec.

As a general rule you multiply speed X 8 to get maximum transfer rate.

So as an example ddr400 pc3200 ram runs at 400mhz so 400 x 8 = 3200 or pc3200 for the maximum transfer rate.

 

[808Alaska]

ok that makes sense. why is by multiplied by 8 though? just curious, and does that value ever change?

 

[darsunt]

I believe 8 stands for 8 bits in a byte

 

[Hefemeister]

The maximum transfer rate for a memory module can be calculated thru the following formula:

Maximum Theoretical Transfer Rate = clock x number of bits / 8

Since DIMM modules transfer 64 bits at a time, “number of bits” will be 64. As 64 / 8 equals to 8, we can simplify this formula to:

Maximum Theoretical Transfer Rate = clock x 8

Understanding RAM Timings | Hardware Secrets

 

[808Alaska]

Wow thats cool. lol. its like im understanding a different language here, haha. but it all makes sense so its all good.