Reading RAM Tags

[JacoFett]

What does '2Rx16' and '32Mx64' mean when referring to RAM labels? Also, more specifically, what do the R and M mean? Could you break down 'PC2700S-2533-0-A1' as well please?

Thank you.

 

[brispuss]

2Rx16 = two Ranks of memory chips at memory data width of 16 bits are being used on a memory module.

A rank of memory chips means that there are so many memory chips being used on the memory module which is equivalent to a total of 64 bits of memory data. In other words one rank of memory chips = 64 bits of memory data. So two ranks of memory chips means there are two lots of one rank memory chips used and so there are therefore two lots 64 bit memory data available.

32Mx64 = memory chip architecture used on each memory chip is equivalent to 32 million (M) memory locations times (x) 64 bits total memory data width.

PC2700 = a DDR type memory module that has a theoretical maximum bandwidth of 2700 million bytes per second.

S = that the module is a SODIMM type; SODIMM = Small Outline Dual Inline Memory Module.

2533 = the memory module has a CAS Latency of 2.5 memory clock cycles, and a row address to column address delay ( = t[sub]RCD[/sub]) of 3 memory clock cycles, and a row precharge time ( = t[sub]RP[/sub]) of 3 memory clock cycles.

0 = version/revision number of the SPD (Serial Presence Detect) data used on the memory module. This detail is not really important to know.

A1 = memory module design version used for its construction. Again this detail is not really important.