Originally Posted by DRKreiger
I really didn't think that the dual rank config made a difference, but it does. Even if it is minimal
All other things being equal, dual rank generally means higher bandwidth (more ranks to interleave), slightly worse latency, and a bit more difficulty OCing.
Also, more ICs for a given memory capacity means lower density ICs, which means tRFC can usually be tighter.
Originally Posted by xenkw0n
That's interesting. I suppose it is dual rank but with only 8 chips.
There are 16-bit ICs that only need four to make a rank, but this configuration is extremely rare for DDR3 UDIMMs.
I looked up my 4GiB sticks on Crucial's site and they are listed as "512Meg x 64", which implies 4Gib DRAM devices, but my sticks clearly have sixteen 2Gib ICs each.
GIven that DRKreiger has stated he sees ICs on both sides but didn't mention there only being four on each side (and there isn't really such thing as a dummy/blank IC, they are just left off if not needed) I think these Crucial Ballistix 8GiB DIMMs almost certainly have sixteen 8-bit ICs, of 4Gib density, with each rank being eight ICs.
8Gib DDR3 ICs are also very expensive and would likely not be found on memory DIMMs this inexpensive. Furthermore, they have extremely loose tRFC requirements, and the tRFC listed on DRKreiger's stick's SPD/XMP profiles correspond to 4Gib ICs.