Quoting Segher Boessenkool segher@kernel.crashing.org:
Anyone know what the mathmatical calculation is to determine a Dimms "Page Size"?? I found this but it does not seem to work:
Page size = (2^col)*bus_width where, col = number of column address lines (SPD byte 4: Number of Column Addresses) bus_width = number of data(DQ) lines (???SPD byte 13: SDRAM Device
Width???)
"device width" is the number of data lines per DRAM chip on your DIMM. This isn't the same as the number of data lines on the DIMM itself; that is 64 usually (not counting the ECC bits). This info is in the SPD as well.
Segher
Ok, so that must be byte 6: Data Width of Assembly. It still does not seem to compute though.
col = 9 /* SPD byte 4: Number of Column Addresses */ bus_width = 64 /* SPD byte 6: Data Width of Assembly */
page_size = (2^col)*bus_width
2^9 = 512
5184 = 81 * 64
512 * 64 = 32K
Myles
Which is not correct because the DIMM has a 4k page size. (According to it's datasheet).
Please Help.